C++ Output Implementations ///// Are there ways to perform faster ?

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---------- Purpose: ----------

First, sorry for my bad English.
Second, I know there are lots of topics about this. But after solving a problem that need FastIO, I feel interested in FastIO and decide to do the implementations and comparing them. But it maybe time-consuming so I make this post for ones who maybe try to find the Effeciency-Simple-IO, so you can save time instead of searching more.
Third, usually it is need not to use FastIO. In the contest, they usually have twice or more time of the solutions code than the given time limitation. Dont worry about faster IO if it is not needed, you should improve your algorithms first, maybe you can use Bitwise Operations for x8 x32 x64 faster.
Fourth, if the problem need to be solve in O(n) ~ O(n log n), and your algorithms work in O(n ^ 2), this Micro-Optimization doesnt help you at all (maybe you will get some more points but hard get AC), you should change the algorithms for further approach.
Final, for some problems that needed to be solved by FastIO, you can use the suitable template and modify it for your solving the problem. Dont use the template if you dont really know how to use (I may add a guide path to the post in the future)
Conclusion, this post is about comparing the implementations for each version of C++ language and you should choose the most suitable for you.

Here are some implementations to output numbers I found

Time to write first 10.000.000 non-negative numbers

(base on Codeforces Custom Test // GNU G++ 17 7.3.0 // GNU G++ 14 6.4.0 // GNU G++ 11 5.1.0)

Sort by GNU G++ 17 7.3.0

Putchar Non-recursive Dividing Implementation: 3649ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Recursive Implementation: 3510ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Reverse Implementation: 3462ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Non-recursive toString Implementation: 3369ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Printf Implementation: 1762ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", q);
    return 0;
}

synchronized(off) Cout Implementation: 1356ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

synchronized(true) Cout Implementation: 1060ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Normal Cout Implementation: 1045ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 919ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 842ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 701ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 670ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

fwrite buffer Implementation: 545ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(q); Flusher();
    return 0;
}

Sort by GNU G++ 14 6.4.0

Putchar Non-recursive Dividing Implementation: 3525ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Reverse Implementation: 3447ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Recursive Implementation: 3354ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Non-recursive toString Implementation: 3353ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Printf Implementation: 1669ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", q);
    return 0;
}

synchronized(off) Cout Implementation: 1356ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

synchronized(true) Cout Implementation: 1091ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Normal Cout Implementation: 1075ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 888ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 685ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 561ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 546ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

fwrite buffer Implementation: 498ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(q); Flusher();
    return 0;
}

Sort by GNU G++ 11 5.1.0

synchronized(off) Cout Implementation: 2901ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

synchronized(true) Cout Implementation: 2901ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Normal Cout Implementation: 2900ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << q;
    return 0;
}

Printf Implementation: 1918ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", q);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 795ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Reverse Implementation: 592ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Non-recursive toString Implementation: 451ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

Putchar Recursive Implementation: 389ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(q);
    return 0;
}

fwrite buffer Implementation: 405ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(q); Flusher();
    return 0;
}

Time to write 1.000 times first 10000 numbers

(base on Codeforces Custom Test // GNU G++ 17 7.3.0 // GNU G++ 14 6.4.0 // GNU G++ 11 5.1.0)

Sort by GNU G++ 17 7.3.0

Putchar Reverse Implementation: 1981ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 1980ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Non-recursive toString Implementation: 1934ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Recursive Implementation: 1887ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Printf Implementation: 1216ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            printf("%d", i);
    return 0;
}

synchronized(on) Implementation: 873ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Normal Cout Implementation: 873ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

synchronized(off) Cout Implementation: 857ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 483ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 467ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 358ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 373ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

fwrite buffer Implementation: 311ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;


int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    Flusher();
    return 0;
}

Sort by GNU G++ 14 6.4.0

Putchar Reverse Implementation: 1996ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 1996ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Non-recursive toString Implementation: 1903ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Recursive Implementation: 1871ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Printf Implementation: 1153ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            printf("%d", i);
    return 0;
}

synchronized(off) Cout Implementation: 920ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

synchronized(on) Implementation: 888ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Normal Cout Implementation: 873ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 452ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 404ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 296ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 295ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

fwrite buffer Implementation: 233ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;


int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    Flusher();
    return 0;
}

Sort by GNU G++ 11 5.1.0

synchronized(on) Implementation: 2698ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Normal Cout Implementation: 2698ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

synchronized(off) Cout Implementation: 2620ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            cout << i;
    return 0;
}

Printf Implementation: 1403ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            printf("%d", i);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 405ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        putchar(x / p + '0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Reverse Implementation: 343ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

fwrite buffer Implementation: 265ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;


int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    Flusher();
    return 0;
}

Putchar Non-recursive toString Implementation: 249ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Putchar Recursive Implementation: 233ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e3;
    while (q--)
        for (int i = 0; i <= 1e4; ++i)
            writeInt(i);
    return 0;
}

Time to write first 10.000.000 non-positive numbers

(base on Codeforces Custom Test // GNU G++ 17 7.3.0 // GNU G++ 14 6.4.0 // GNU G++ 11 5.1.0)

Sort by GNU G++ 17 7.3.0

Putchar Non-recursive toString Implementation: 3946ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Reverse Implementation: 3930ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Recursive Implementation: 3915ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-');
    writeRec(abs(x));
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 3883ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10) putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Printf Implementation: 1808ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", -q);
    return 0;
}

synchronized(off) Cout Implementation: 1481ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

synchronized(true) Cout Implementation: 1092ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Normal Cout Implementation: 1092ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 1045ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 857ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 795ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 779ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

fwrite buffer Implementation: 561ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q); Flusher();
    return 0;
}

Sort by GNU G++ 14 6.4.0

Putchar Reverse Implementation: 3899ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Recursive Implementation: 3899ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-');
    writeRec(abs(x));
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 3883ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10) putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Non-recursive toString Implementation: 3860ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Printf Implementation: 1762ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", -q);
    return 0;
}

synchronized(off) Cout Implementation: 1512ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Normal Cout Implementation: 1153ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

synchronized(true) Cout Implementation: 1092ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Unlocked-Putchar Non-recursive Dividing Implementation: 951ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10)
        _putchar_nolock(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Reverse Implementation: 732ms

#include <iostream>

using namespace std;

#define pc _putchar_nolock
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Recursive Implementation: 655ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    _putchar_nolock(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) _putchar_nolock('-'), x = -x;
    writeRec(x);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Unlocked-Putchar Non-recursive toString Implementation: 638ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) _putchar_nolock('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) _putchar_nolock(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

fwrite buffer Implementation: 529ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q); Flusher();
    return 0;
}

Sort by GNU G++ 11 5.1.0

synchronized(true) Cout Implementation: 2901ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Normal Cout Implementation: 2901ms

#include <iostream>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

synchronized(off) Cout Implementation: 2885ms

#include <iostream>

using namespace std;

int main()
{
    ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
    int q = 1e7;
    while (q--) cout << -q;
    return 0;
}

Printf Implementation: 1950ms

#include <cstdio>

using namespace std;

int main()
{
    int q = 1e7;
    while (q--) printf("%d", -q);
    return 0;
}

Putchar Non-recursive Dividing Implementation: 810ms

#include <iostream>

using namespace std;

inline void writeInt(int x)
{
    if (x < 0) putchar('-'), x = -x;
    int p = 1;
    for (int t = x / 10; t > 0; t /= 10)
        p *= 10;
    for (; p > 0; x %= p, p /= 10) putchar(x / p + '0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Reverse Implementation: 624ms

#include <iostream>

using namespace std;

#define pc putchar
inline void writeInt(int n)
{
    if (n < 0) pc('-'), n = -n;
    if (!n) return (void)pc('0');
    int t = n, cnt = 0, rev = 0;
    while (!(t%10)) { cnt++; t /= 10;}
    do {rev=rev*10 + n%10;} while(n /= 10); 
    do {pc(rev % 10 + 48);} while(rev /= 10);
    while (cnt--) pc('0');
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

fwrite buffer Implementation: 483ms

#include <iostream>

using namespace std;

static const int buf_len = (1 << 14);
static const int buf_max = (1 << 04);
static char buf_out[buf_len];
static char buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x) {
    if (buf_pos == buf_len) fwrite(buf_out, 1, buf_len, stdout), buf_pos = 0;
    buf_out[buf_pos++] = x;
}

inline void writeInt(int x, char end = 0) {
    if (x < 0) writeChar('-'), x = -x;
    int n = 0;
    do buf_num[n++] = x % 10 + '0'; while(x /= 10);
    while (n--) writeChar(buf_num[n]);
    if (end) writeChar(end);
}

struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q); Flusher();
    return 0;
}

Putchar Non-recursive toString Implementation: 483ms

#include <iostream>

using namespace std;

char os[20];
inline void writeInt(int n)
{
    if (n < 0) putchar('-'), n = -n;
    int i=0;
    do os[i++] = n%10; while(n/=10);
    while (i--) putchar(os[i] + 48);
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Putchar Recursive Implementation: 452ms

#include <iostream>

using namespace std;

inline void writeRec(int n) {
    if (n > 9) writeRec(n / 10);
    putchar(char(n % 10 + '0'));
}

inline void writeInt(int x)
{
    if (x < 0) putchar('-');
    writeRec(abs(x));
}

int main()
{
    int q = 1e7;
    while (q--) writeInt(-q);
    return 0;
}

Single Line Template

Putchar Non-recursive toString Implementation

char os[20];
inline void writeInt(int n){if(n<0)putchar('-'),n=-n;int i=0;do{os[i++]=n%10;}while(n/=10);while(i--)putchar(os[i]+48);}

Putchar Non-recursive Dividing Implementation

inline void writeInt(int x){if(x<0)putchar('-'),x=-x;int p=1;for(int t=x/10;t>0;t/=10)p*=10;for(;p>0;x%=p,p/=10)putchar(x/p+'0');}

Putchar Reverse Implementation

#define pc putchar
inline void writeInt(int n){if(n<0)pc('-'),n=-n;if(!n)return(void)pc('0');int t=n,cnt=0,rev=0;while(!(t%10)){cnt++;t/=10;}do{rev=rev*10+n%10;}while(n/=10);do{pc(rev%10+48);}while(rev/=10);while(cnt--)pc('0');}

Putchar Recursive Implementation

inline void writeRec(int n){if(n>9)writeRec(n/10);putchar(char(n%10+'0'));}
inline void writeInt(int x){if(x<0)putchar('-');writeRec(abs(x));}

Unlocked-Putchar Non-recursive toString Implementation

char os[20];
inline void writeInt(int n){if(n<0)_putchar_nolock('-'),n=-n;int i=0;do{os[i++]=n%10;}while(n/=10);while(i--)_putchar_nolock(os[i]+48);}

Unlocked-Putchar Non-recursive Dividing Implementation

inline void writeInt(int x){if(x<0)_putchar_nolock('-'),x=-x;int p=1;for(int t=x/10;t>0;t/=10)p*=10;for(;p>0;x%=p,p/=10)_putchar_nolock(x/p+'0');}

Unlocked-Putchar Reverse Implementation

#define pc _putchar_nolock
inline void writeInt(int n){if(n<0)pc('-'),n=-n;if(!n)return(void)pc('0');int t=n,cnt=0,rev=0;while(!(t%10)){cnt++;t/=10;}do{rev=rev*10+n%10;}while(n/=10);do{pc(rev%10+48);}while(rev/=10);while(cnt--)pc('0');}

Unlocked-Putchar Recursive Implementation

inline void writeRec(int n){if(n>9)writeRec(n/10);_putchar_nolock(char(n%10+'0'));}
inline void writeInt(int x){if(x<0)_putchar_nolock('-');writeRec(abs(x));}

Printf Implementation

printf("%d", x);

synchronized(off) Implementation

ios::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);

synchronized(true) Implementation

ios::sync_with_stdio(true),cin.tie(NULL),cout.tie(NULL);

Cout Implementation

cout << x;

fwrite buffer Implementation

static const int buf_len = (1 << 14), buf_max = (1 << 04);
static char buf_out[buf_len], buf_num[buf_max];
static int buf_pos = 0;

inline void writeChar(int x){if(buf_pos==buf_len)fwrite(buf_out,1,buf_len,stdout),buf_pos=0;buf_out[buf_pos++]=x;}
inline void writeInt(int x,char end=0){if(x<0)writeChar('-'),x=-x;int n=0;do{buf_num[n++]=x%10+'0';}while(x/=10);while(n--)writeChar(buf_num[n]);if(end)writeChar(end);}
struct Flusher{~Flusher(){if(buf_pos)fwrite(buf_out, 1, buf_pos, stdout),buf_pos=0;}}flusher;

---------- About: ----------

---------- Similiar Topic: ----------

---------- Planning: ----------

Test about random 10.000.000 big numbers
Test with Microsoft Visual C++ 2010
Test with Microsoft Visual C++ 2017
More implementations (Actually the post is about Faster and Faster Short Output Implementation but I will add some for speed comparing)
New output types (long long, double, string)

Rev.	By	When	Δ	Comment
en44	SPyofgame	2020-06-06 17:24:10	2	Tiny change: '\n\n\n\n\n' -> '\n\n\n\n\n\n'
en43	SPyofgame	2020-06-01 04:54:23	24664	Add Sort by Microsoft Visual C++ 2010 \| Add Sort by Microsoft Visual C++ 2017
en42	SPyofgame	2020-03-11 17:17:22	246
en41	SPyofgame	2020-03-11 17:16:30	585
en40	SPyofgame	2020-03-11 17:07:19	1028
en39	SPyofgame	2020-03-11 16:19:02	5	Tiny change: '\n- _[C++ Output Implem' -> '\n- _[C++ Input Implem'
en38	SPyofgame	2020-03-11 16:17:54	828
en37	SPyofgame	2020-03-11 16:00:33	163
en36	SPyofgame	2020-03-11 15:32:22	3
en35	SPyofgame	2020-03-11 13:43:24	46	Tiny change: '-- \n\n- _Test ' -> '-- \n\n- _Start working on `Input Implementation`_\n- _Test '
en34	SPyofgame	2020-03-11 12:13:31	13359
en33	SPyofgame	2020-03-10 17:02:27	66
en32	SPyofgame	2020-03-10 16:57:31	2020
en31	SPyofgame	2020-03-10 16:45:15	17395
en30	SPyofgame	2020-03-10 15:13:24	436
en29	SPyofgame	2020-03-10 15:04:53	11184
en28	SPyofgame	2020-03-09 17:08:42	23	Tiny change: '_\n- _New type of implementations (long lo' -> '_\n- _New output types (long lo'
en27	SPyofgame	2020-03-09 17:08:00	107
en26	SPyofgame	2020-03-09 17:04:42	56
en25	SPyofgame	2020-03-09 17:02:11	259	Tiny change: ' 14 6.4.0`_\n- _Test' -> ' 14 6.4.0` for who_\n- _Test'
en24	SPyofgame	2020-03-08 14:31:46	1	Tiny change: 'ementation to output' -> 'ementations to output'
en23	SPyofgame	2020-03-08 13:35:10	56
en22	SPyofgame	2020-03-08 13:34:24	62
en21	SPyofgame	2020-03-08 13:32:27	151
en20	SPyofgame	2020-03-08 13:31:05	22
en19	SPyofgame	2020-03-08 13:30:04	643
en18	SPyofgame	2020-03-08 13:23:01	2	Tiny change: 't[buf_len]. buf_num[b' -> 't[buf_len], buf_num[b'
en17	SPyofgame	2020-03-08 13:21:59	2393
en16	SPyofgame	2020-03-08 06:24:35	1405
en15	SPyofgame	2020-03-08 05:43:13	2610
en14	SPyofgame	2020-03-07 21:43:54	1881
en13	SPyofgame	2020-03-07 21:05:24	16
en12	SPyofgame	2020-03-07 21:00:12	68
en11	SPyofgame	2020-03-07 17:34:09	40
en10	SPyofgame	2020-03-07 13:05:13	3986
en9	SPyofgame	2020-03-07 12:49:33	421
en8	SPyofgame	2020-03-07 12:34:04	128
en7	SPyofgame	2020-03-07 12:32:50	28
en6	SPyofgame	2020-03-07 12:32:25	200
en5	SPyofgame	2020-03-07 12:17:57	217
en4	SPyofgame	2020-03-07 12:16:16	502
en3	SPyofgame	2020-03-07 12:12:35	9
en2	SPyofgame	2020-03-07 12:11:11	16	Tiny change: ' summary="Third Implement' -> ' summary="synchronized(off) Implement'
en1	SPyofgame	2020-03-07 12:10:26	2318	Initial revision (published)

Here are some implementations to output numbers I found

History