Submission #1365578

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define File(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout)
#define maxn 100010

using namespace std;
typedef long long llg;

int hd[maxn],nt[maxn<<1],to[maxn<<1],c[maxn<<1],tt;
int n,m,co[maxn],SIZ,cm,du[maxn];
bool vis[maxn],su;
llg ans,ci[3];

void dfs(int u){
	vis[u]=1; SIZ++; ci[co[u]]++; cm+=du[u];
	for(int i=hd[u],v;v=to[i],i;i=nt[i])
		if(!vis[v]) co[v]=(co[u]+c[i])%3,dfs(v);
		else if(co[v]!=(co[u]+c[i])%3) su=1;
}

int main(){
	scanf("%d %d",&n,&m);
	for(int i=1,x,y;i<=m;i++){
		scanf("%d %d",&x,&y);
		to[++tt]=y;nt[tt]=hd[x];hd[x]=tt;
		to[++tt]=x;nt[tt]=hd[y];hd[y]=tt;
		c[tt-1]=1; c[tt]=2; du[x]++,du[y]++;
	}
	for(int i=1,now;i<=n;i++)
		if(!vis[i]){
			dfs(i);
			if(su) ans+=1ll*SIZ*SIZ;
			else{
				now=(!ci[0])+(!ci[1])+(!ci[2]);
				if(!now) ans+=ci[0]*ci[1]+ci[1]*ci[2]+ci[2]*ci[0];
				else ans+=cm>>1;
			}
			ci[0]=ci[1]=ci[2]=0; SIZ=cm=0; su=0;
		}
	printf("%lld",ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:25:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
                      ^
./Main.cpp:27:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&x,&y);
                       ^

Judge Result