Submission #1677941

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Source Code Expand

#include<cstdio>
#include<algorithm>
#define fo(i,a,b) for(i=a;i<=b;i++)
using namespace std;
typedef long long ll;
const int maxn=100000+10;
int fa[maxn],co[maxn];
bool bz[maxn],pd[maxn];
int i,j,k,l,r,t,n,m,cnt;
ll ans;
int getfa(int x){
	if (!fa[x]) return x;
	int t=getfa(fa[x]);
	co[x]^=co[fa[x]];
	return fa[x]=t;
}
int main(){
	scanf("%d%d",&n,&m);
	fo(i,1,m){
		scanf("%d%d",&j,&k);
		bz[j]=1;bz[k]=1;
		l=getfa(j);r=getfa(k);
		if (l<r){
			swap(l,r);
			swap(j,k);
		}
		if (l==r&&co[j]==co[k]) pd[l]=1;
		if (l==r) continue;
		pd[r]|=pd[l];
		fa[l]=r;
		co[l]=co[j]^co[k]^1;
	}
	fo(i,1,n)
		if (!bz[i]) cnt++;
	ans=(ll)cnt*(n-cnt)*2+(ll)cnt*cnt;
	cnt=0;
	fo(i,1,n)
		if (bz[i]&&!fa[i]) cnt++;
	ans+=(ll)cnt*cnt;
	cnt=0;
	fo(i,1,n)
		if (bz[i]&&fa[i]){
			k=getfa(i);
			if (!pd[k]&&co[i]!=co[k]) cnt++;
		}
	fo(i,1,n)
		if (bz[i]&&!fa[i]&&!pd[i]) ans+=(ll)cnt;
	printf("%lld\n",ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:18:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
./Main.cpp:20:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&j,&k);
                      ^

Judge Result