why downvotes ? it's a question

Ok you can use this code for all problem !

#include<iostream>
using namespace std;
# ifdef __GNUC__       
# if __cplusplus > 199711L
# include <unordered_map>	
# else
# include <tr1/unordered_map>
using namespace std::tr1;
# endif
# else
# include <unordered_map>
# endif

#define VA_NUM_ARGS(...) VA_NUM_ARGS_IMPL_((0,__VA_ARGS__, 5,4,3,2,1))
#define VA_NUM_ARGS_IMPL_(tuple) VA_NUM_ARGS_IMPL tuple
#define VA_NUM_ARGS_IMPL(_0,_1,_2,_3,_4,_5,N,...) N

#define macro_dispatcher(macro, ...) macro_dispatcher_(macro, VA_NUM_ARGS(__VA_ARGS__))
#define macro_dispatcher_(macro, nargs) macro_dispatcher__(macro, nargs)
#define macro_dispatcher__(macro, nargs) macro_dispatcher___(macro, nargs)
#define macro_dispatcher___(macro, nargs) macro ## nargs

#define DBN1(a)			std::cerr<<#a<<"="<<(a)<<"\n"
#define DBN2(a,b)		std::cerr<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<"\n"
#define DBN3(a,b,c)		std::cerr<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<"\n"
#define DBN4(a,b,c,d)	std::cerr<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<", "<<#d<<"="<<(d)<<"\n"
#define DBN5(a,b,c,d,e)	std::cerr<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<", "<<#d<<"="<<(d)<<", "<<#e<<"="<<(e)<<"\n"

#define DEB(x) std::cerr<<#x<<"="<<(x)<<"  "

#ifdef DEBUG
#define DB(x) DEB(x)
#define DBN(...) macro_dispatcher(DBN, __VA_ARGS__)(__VA_ARGS__)
#define DA(a,n) cout<<#a<<"=["; printarray(a,n); cout<<"]\n"
#define DAR(a,n,s) cout<<#a<<"["<<s<<"-"<<n-1<<"]=["; printarray(a,n,s); cout<<"]\n"
#else
#define DB(x) ((void)42)
#define DBN(...) ((void)42)
#define DA(a,n) ((void)42)
#define DAR(a,n,s) ((void)42)
#endif

double __begin;
#define DTIME(ccc) __begin = clock(); ccc; std::cerr<<"Time of work = "<<(clock()-__begin)/CLOCKS_PER_SEC<<std::endl; 

#define mp make_pair
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
typedef vector<int> vi;
typedef vector<long long> vll;

template<typename T1,typename T2,typename T3>
struct triple{T1 a;T2 b;T3 c;triple(){};triple(T1 _a,T2 _b, T3 _c):a(_a),b(_b),c(_c){}};
#define tri triple<int,int,int>
#define trl triple<ll,ll,ll>
template<typename T1,typename T2,typename T3>
bool operator<(const triple<T1,T2,T3> &t1,const triple<T1,T2,T3> &t2){if (t1.a!=t2.a) return t1.a<t2.a; else return t1.b<t2.b;}
template<typename T1, typename T2, typename T3>
inline std::ostream& operator << (std::ostream& os, const triple<T1, T2, T3>& t){ return os << "(" << t.a << ", " << t.b << ", " << t.c << ")"; }


#define FI(n) for(int i=0;i<n;i++)
#define FI1(n) for(int i=1;i<n;i++)
#define FJ(n) for(int j=0;j<n;j++)
#define FJ1(n) for(int j=1;j<n;j++)
#define FJI for(int j=0;j<i;j++)
#define FJI1 for(int j=1;j<i;j++)
#define FJIE for(int j=0;j<=i;j++)
#define FJIE1 for(int j=1;j<=i;j++)
#define For(i,a,b) for(int i=a;i<b;i++)

// Input macros
#define S(n)                        scanf("%d",&n)
#define S2(a,b)						scanf("%d%d",&a,&b)
#define Sc(n)                       scanf("%c",&n)
#define Sl(n)                       scanf("%I64d",&n)
#define Sl2(a,b)					scanf("%I64d%I63d",&a,&b)
#define Sf(n)                       scanf("%lf",&n)
#define Sf2(a,b)                    scanf("%lf%lf",&a,&b)

//Output macros
#define Pr(n)                       printf("%d ",n)
#define Prn(n)                      printf("%d\n",n)
#define Prc(n)                      printf("%c",n)
#define Prcn(n)                     printf("%c\n",n)
#define Prl(n)                      printf("%I64d ",n)
#define Prln(n)                     printf("%I64d\n",n)
#define Prf(n)                      printf("%lf ",n)
#define Prfn(n)                     printf("%lf\n",n)
#define Prs(n)                      printf("%s ",n)
#define Prsn(n)                     printf("%s\n",n)

//STL containers
#define foreach(v, c)               for( auto v = (c).begin();  v != (c).end(); ++v)
#define all(a)                      a.begin(), a.end()
#define in(a,b)                     ((b).find(a) != (b).end())
#define in2(a,b)                    (find(all(b),a) != (b).end())
#define pb                          push_back
#define sz(a)                       ((int)(a.size()))
#define svi(vec,n) FI(n) S(vec[y])
#define svl(vec,n) FI(n) Sl(vec[y])
#define IT ::iterator

//int some_primes[10] = {100271, 500179, 1000003, 2000227, 5000321}
//fill char arrays
#define fill(a,v)                    memset(a, v, sizeof (a))

inline int bits_count(int v){v=v-((v>>1)&0x55555555);v=(v&0x33333333)+((v>>2)&0x33333333);return((v+(v>>4)&0xF0F0F0F)*0x1010101)>>24;}
inline int bits_count(ll v){ int t = v >> 32; int p = (v & ((1LL << 32) - 1)); return bits_count(t) + bits_count(p); }
unsigned int reverse_bits(register unsigned int x){x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));x = (((x & 0xff00ff00) >> 8) | ((x & 0x00ff00ff) << 8));return((x >> 16) | (x << 16));}
inline int sign(int x){return (x >> 31) | (-x >> 31);}
inline bool ispow2(int x){return (x!=0 && (x&(x-1))==0);}
#define checkbit(n,b)        ( (n >> b) & 1)
#define INDEX(arr,ind)       (lower_bound(all(arr),ind)-arr.begin())
#define sor(a)  sort(all(a))
#define rsor(a) sort(all(a)); reverse(all(a));

//STL output ********************************
template<typename T1,typename T2>inline std::ostream& operator << (std::ostream& os, const std::pair<T1, T2>& p){return os << "(" << p.first << ", " << p.second << ")";}
template<typename T>inline std::ostream &operator<<(std::ostream &os,const std::vector<T>& v){bool first=true;os<<"[";for(unsigned int i=0;i<v.size();i++){if(!first)os<<", ";os<<v[i];first=false;}return os<<"]";}
template<typename T>inline std::ostream &operator<<(std::ostream &os,const std::set<T>&v){bool first=true;os << "[";for(typename std::set<T>::const_iterator ii=v.begin();ii!=v.end();++ii){if(!first)os<<", ";os<<*ii;first=false;}return os<<"]";}
template<typename T1, typename T2>inline std::ostream &operator << (std::ostream & os,const std::map<T1, T2>& v){bool first = true; os << "[";for (typename std::map<T1,T2>::const_iterator ii =v.begin();ii!=v.end();++ii){if(!first)os<<", ";os<<*ii;first=false;}return os<<"]";}
template<typename T,typename T2>void printarray(T  a[],T2 sz,T2 beg=0){for(T2 i=beg;i<sz;i++) cout<<a[i]<<" ";cout<<endl;}

#define FREIN(FILE) freopen(FILE,"rt",stdin)
#define FREOUT(FILE) freopen(FILE,"wt",stdout)

#define sqr(x) ((x)*(x))
#define sqrt(x) sqrt(1.0*(x))
#define pow(x,n) pow(1.0*(x),n)

inline ll binpow(ll x,ll n){ll res=1;while(n){if(n&1)res*=x;x*=x;n>>=1;}return res;}
inline ll powmod(ll x,ll n, ll _mod){ll res=1;while(n){if(n&1)res=(res*x)%_mod;x=(x*x)%_mod;n>>=1;}return res;}
inline ll gcd(ll a,ll b){ll t;while(b){a=a%b;t=a;a=b;b=t;}return a;}
inline int gcd(int a,int b){int t;while(b){a=a%b;t=a;a=b;b=t;}return a;}
inline ll lcm(int a,int b){return a/gcd(a,b)*(ll)b;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
inline ll gcd(ll a,ll b,ll c){return gcd(gcd(a,b),c);}
inline int gcd(int a,int b,int c){return gcd(gcd(a,b),c);}
inline ll lcm(ll a,ll b,ll c){return lcm(lcm(a,b),c);}
inline ll lcm(int a,int b,int c){return lcm(lcm(a,b),(ll)c);}

inline ll max(ll a,ll b){return (a>b)?a:b;}
inline int max(int a,int b){return (a>b)?a:b;}
inline double max(double a,double b){return (a>b)?a:b;}
inline ll max(ll a,ll b,ll c){return max(a,max(b,c));}
inline int max(int a,int b,int c){return max(a,max(b,c));}
inline double max(double a,double b,double c){return max(a,max(b,c));}
inline ll min(ll a,ll b){return (a<b)?a:b;}
inline int min(int a,int b){return (a<b)?a:b;}
inline double min(double a,double b){return (a<b)?a:b;}
inline ll min(ll a,ll b,ll c){return min(a,min(b,c));}
inline int min(int a,int b,int c){return min(a,min(b,c));}
inline double min(double a,double b,double c){return min(a,min(b,c));}

template<class T>
inline void getar(T a, int n, int m){ for (int i = 0; i < n; i++) for (int j = 0; j < m;++j) { scanf("%d", &a[i][j]); } }
inline void getar(int *a, int n){ for (int ii = 0; ii < n; ii++){ scanf("%d", a + ii); } }
inline void getar(pii *a, int n){ for (int ii = 0; ii < n; ii++){ scanf("%d%d", &a[ii].first, &a[ii].second); } }
inline void getar(ll *a, int n){ for (int ii = 0; ii < n; ii++){ scanf("%I64d", a + ii); } }
template<class T>
inline void cinarr(T a, int n){ for (int i=0;i<n;++i) cin >> a[i];}
// Useful constants

#define INF			1011111111
#define EPS			(double)1e-8
#define mod			1000000007
#define PI			3.14159265358979
//*******************************************************************************/
#endif

vector<pii> v[100010];
int calc[100010];
bool used[100010];
vector<int> rev[100010];

int x[100001];
int y[100001];
int len[100010];
double pd[100010];
map<pii, int> MAP;
int n;

double get(ll x, ll y){
	ll tot = n * (n - 1ll) * (n - 2ll) / 6;

	ll cur = x * (x - 1) / 2 * y + y * (y - 1) / 2 * x;
	return cur * 1.0 / tot;
}
int go(int cur){
	used[cur] = true;
	int res = 1;
	for (pii p : v[cur]){
		int to = p.first;
		int len = p.second;

		if (used[to]) continue;
		int foo = go(to);
		res += foo;

		int qw = MAP[{cur, to}];

		pd[MAP[{cur, to}]] = get(foo, n - foo);
	}
	calc[cur] = res;
	
	return res;
}
int main(){
cout<<"Don't cheat !";
}

Sadly this guy joined codeforces only to get downvotes.

I don't know why but i can't stop laughing this post. I think it's cause it seems to be so naive.