Submission #1588986

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Source Code Expand

#include<bits/stdc++.h>
#define MAXN 1000000+10 
using namespace std;
int n,m,I,P,Q;
int cnt,head[MAXN],to[MAXN],nxt[MAXN],linker[MAXN];
bool f,vis[MAXN];
void add(int x,int y){
	cnt++;
	to[cnt]=y;
	nxt[cnt]=head[x];
	head[x]=cnt;
}
void dfs(int x,int fa){
	vis[x]=true;
	linker[x]=linker[fa]^1;
	for(int i=head[x];i;i=nxt[i]){
		int y=to[i];
		if(y!=fa){
			if(vis[y])
				if(linker[x]==linker[y])f=true;
			else dfs(y,x);
		}
	}
}
int main(){
	scanf("%d%d",&n,&m);
	int x,y;
	for(int i=0;i<m;i++){
		cin>>x>>y;
		add(x,y);
		add(y,x);
	}
	for(int i=1;i<=n;i++)
		if(!vis[i]){
			if(!head[i]){
				I++;
				vis[i]=true;
				continue;
			}
			f=false;
			dfs(i,0);
			if(f)P++;
			else Q++;
		}
	long long ans=2LL*I*n-1LL*I*I+1LL*P*P+2LL*P*Q+2LL*Q*Q;
	printf("%lld\n",ans);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:26:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^

Judge Result