Submission #956953

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Source Code Expand

#include <cstdio>
#include <vector>
#include <queue>
using namespace std;

int main()
{
  int n,m;
  scanf("%d%d",&n,&m);
  vector<vector<int> > e(n),r(n);
  for(int i=0;i<m;i++){
    int a,b;
    scanf("%d%d",&a,&b);
    a--;
    b--;
    e[a].push_back(b);
    r[b].push_back(a);
  }
  long long ans=0;
  static int V[100000];
  for(int i=0;i<n;i++){
    V[i]=-1;
  }
  for(int i=0;i<n;i++){
    if(V[i]!=-1){
      continue;
    }
    queue<int> Q;
    Q.push(i);
    bool F=0;
    int c=0,C[3]={0};
    V[i]=0;
    C[0]++;
    while(!Q.empty()){
      int j=Q.front();
      Q.pop();
      int v=V[j];
      for(int x=0;x<e[j].size();x++){
	int k=e[j][x];
	c++;
	if(V[k]==-1){
	  V[k]=(v+1)%3;
	  C[V[k]]++;
	  Q.push(k);
	}
	else if(V[k]!=(v+1)%3){
	  F=1;
	}
      }
      for(int x=0;x<r[j].size();x++){
	int k=r[j][x];
	if(V[k]==-1){
	  V[k]=(v+2)%3;
	  C[V[k]]++;
	  Q.push(k);
	}
	else if(V[k]!=(v+2)%3){
	  F=1;
	}
      }
    }
    if(F){
      int A=C[0]+C[1]+C[2];
      ans+=(long long)A*A;
    }
    else if(C[1]==0||C[2]==0){
      ans+=c;
    }
    else{
      ans+=(long long)C[0]*C[1]+(long long)C[1]*C[2]+(long long)C[2]*C[0];
    }
  }
  printf("%lld\n",ans);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:9:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&n,&m);
                      ^
./Main.cpp:13:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&a,&b);
                        ^

Judge Result