Submission #34663174

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Source Code Expand

#include <bits/stdc++.h>
#include <atcoder/modint>
using mint = atcoder::modint998244353;
using namespace std;
#define rep(i,a,n) for (int i=a;i<(int)n;i++)
#define per(i,a,n) for (int i=n;i-->(int)a;)
int read(){int r;scanf("%d",&r);return r;} // read

mint fac[5000010] = {1};
mint ifac[5000010] = {1};
int a[3];
mint binom(int n,int m){
  if(n < 0 || m > n) return 0;
  return fac[n]*ifac[m]*ifac[n-m];
}

int main(){
  int n = read();
  rep(i,0,3) a[i] = read();
  rep(i,1,n+1) fac[i]=fac[i-1]*i;
  ifac[n] = fac[n].inv();
  per(i,0,n) ifac[i]=ifac[i+1]*(i+1);

  mint f[] = {1,1,1};
  mint sgn = n%2?-1:1;
  mint ans = 0;
  rep(i,0,n+1){
    ans += binom(n, i) * f[0] * f[1] * f[2] * sgn;
    rep(j,0,3) f[j] = f[j]*2 - binom(i,a[j]);
    sgn = -sgn;
  }
  printf("%d\n",ans.val());
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int read()’:
./Main.cpp:7:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    7 | int read(){int r;scanf("%d",&r);return r;} // read
      |                  ~~~~~^~~~~~~~~

Judge Result