Submission #50503511

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Source Code Expand

#include <bits/stdc++.h>
#include <atcoder/modint>
const int MOD=998244353;
using mint = atcoder::static_modint<MOD>;
using namespace std;
typedef long long ll;
ll read(){ll r;scanf("%lld",&r);return r;}
// sum x^0+x^1+...+x^{pwr-1}
mint g(mint x,int pwr){ return (x==1)?pwr:((x.pow(pwr)-1)/(x-1)); }
int main(){
  ll N=read();
  ll M=read();
  ll Q=read();
  mint ans=0;
  mint A=mint(N*(N+1)/2)*(2*M+1);
  mint AQ1 = A.pow(Q-1); // A^{Q-1}
  for(ll i=1;i<=N;i++) {
    mint c = i*(N+1-i);
    mint d = mint(N*(N+1)/2)*(2*M+1)-c*M;
    assert(d != A);
    ans += c*c/(d-A)*AQ1*(M*(M-1)/2)*(g(d/A,Q)-Q);
  }
  printf("%d\n",ans.val());
  return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘ll read()’:
Main.cpp:7:21: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
    7 | ll read(){ll r;scanf("%lld",&r);return r;}
      |                ~~~~~^~~~~~~~~~~

Judge Result