wow

I think the problem G is easier than usual because of the point values.

hope get a positive delta

Hope to Solve ABC

ABC 353 may include:

• Primes ($$$353$$$ is a prime)
• Palindromes

hfhf

mAThCoder

how to do E?

Nice C, D, E

太难了！！！

Can someone help me find out this code get WA for problem G:

https://atcoder.jp/contests/abc353/submissions/53380216

c d e just a little more difficult as it should be in that place.

Why this gives WA for F? Code

can someone please explain what should i do to stop tle in problem C .What should i study to no get tle in next rounds?

I added hints for G: Merchant Takahashi on CF Step

How to G ? I tried to come up with CHT but it may not work cuz i don't know how to deal with t[i]-t[j] :(

Whoa, so many people know about segment trees, it's crazy... after seeing so many ACs on G I expected it to have a simpler solution, but nope...

When I didn't AC Problem C,my brain be like:

Am I crazy or is double hashing really meant to fail on E? I solved it using trie in the end, but struggled with 3 tests failing my double hash.

C >> D , how to solve C ?

include<bits/stdc++.h>

using namespace std;

int N = 1e+8; int main() { ios::sync_with_stdio(0); cin.tie(0); int n; cin >> n; vector vec(n); for(int i=0;i<n;i++){ cin>>vec[i]; } vector vec1; for(int j=0;j<n-1;j++){ for(int i=j+1;i<n;i++){ vec1.push_back(((vec[j])%N+(vec[i])%N)%N); } } long long int sum = accumulate(vec1.begin(),vec1.end(),0); cout<<sum;

}

i wrote this code but i m getting tle but this should be o(n^2) time complexity so is there any way to optimise this code

why is using 1E8 (link) instead of 100000000 (link) giving wrong ans. I submitted 6 different solutions for prob c all of them correct but used 1E8 and none passed

Can someone tell me why problem F got

If you want to build intuition for today's G (specifically the trick of splitting the $$$|.|$$$ operator in DP problems), you can attempt ABC334F : Christmas Present 2. I also created a video and practice contest for the same.

Could someone tell why WA in C? T_T

Code

Join me laughing at myself for what is probably the most overengineered E solution possible boop

Really liked F, really disliked G.

You can check video editorials of E and G here

I wrote a solution of problem D in 50+ lines. Implemented Binary Modular Exponentiation, Grade School Addition and Suffix Sum. I was happy to get AC. Then found out that these guys are writing 10 lines solutions with no fancy algorithms.

Its giving me TLE for C. PLease help me optimize the code

include

using namespace std;

int main() { int n; cin>>n; long long a[n];

for(int i=0;i<n;i++)
{
    cin>>a[i];
}

long ans = 0;

int i = 0;
int j = n-1;

while(i<j)
{
    ans += (a[i]+a[j])%100000000;
    j--;
    if(j==i)
    {
        i++;
        j = n-1;
    }
}

cout<<ans<<endl;

return 0;

}

Dislike F.

in question D it is giving wrong answer only 2 test case passed .

include <bits/stdc++.h>

using namespace std;

define int long long

define fastio \

ios_base::sync_with_stdio(false); \
cin.tie(NULL); \
cout.tie(NULL)

int32_t main() { fastio; int n; cin>>n; int mod=998244353; vector v(n);

for(int i=0;i<n;i++) cin>>v[i];

int ans=0,s=0,m=0;

for(int i=n-1;i>=0;i--){

ans+=v[i]*m+s;

   m+=pow(10, to_string(v[i]).length());

   s+=v[i];

}

cout<<ans%mod;

return 0;

}

unable to find the error

For problem D: I am not able to find the bug, it passes for the example test cases but fails for the rest. Here is my submission for the problem, Can someone please help me debug this?

can someone please debug my submission for G? I'm not able to pinpoint where i'm going wrong, everything seems right on a high level. I'd really appreciate you taking your time for this

Can someone please help- me understand my the below solution for C is failing https://atcoder.jp/contests/abc353/submissions/53411613

Can someone please help with problem E? My solution uses trie and got 41 AC, 7 WA

https://atcoder.jp/contests/abc353/submissions/53412393

Ha the code for the editorial of F is relly strange to me

I thin E is more easier than D. D->60min, E->15min

why no english editorial atcoder_official

include<bits/stdc++.h>

using namespace std;

define int long long

const int mod=998244353;
const int inf=1e18;

int bin_exp(int n,int x,int mod) { if(x==0) { return 1; }

if(x%2==0)
{
    return bin_exp(((n%mod)*(n%mod))%mod,x/2,mod);
}

return ((n%mod)*(bin_exp(((n%mod)*(n%mod))%mod,(x-1)/2,mod))%mod)%mod;

}

int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);

int n;
  cin>>n;
  vector<int>vec(n);
  for(int i=0;i<n;i++)
  {
      cin>>vec[i];
  }

  vector<int>prefix(n);
  prefix[0]=vec[0];
  for(int i=1;i<n;i++)
  {
      prefix[i]=prefix[i-1]+vec[i];
  }

  vector<int>digits(n);
  string some=to_string(vec[0]);
  digits[0]=bin_exp(10,some.size(),mod);

  for(int i=1;i<n;i++)
  {
      some=to_string(vec[i]);
      int whole=bin_exp(10,some.size(),mod);
      whole%mod;

      digits[i]=digits[i-1]+whole;
      digits[i]%mod;
  }

  int ans=0;
  for(int i=0;i<n;i++)
  {
      int ans1=prefix[n-1]-prefix[i];
      ans1=ans1%mod;

      int ans2=digits[n-1]-digits[i];
      ans2%=mod;
      ans2=ans2*vec[i];
      ans2%=mod;

      ans+=ans1+ans2;
      ans=ans%mod;
  }

  cout<<ans<<endl;

  return 0;

}

question number 4 solution