Submission #1846745

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Source Code Expand

#include <bits/stdc++.h>
#ifdef DEMETRIO
#define deb(...) fprintf(stderr,__VA_ARGS__)
#define deb1(x) cerr << #x << " = " << x << endl
#else
#define deb(...) 0
#define deb1(x) 0
#endif
#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define fore(i,a,b) for(int i=a,ThxDem=b;i<ThxDem;++i)
#define SZ(x) ((int)x.size())
using namespace std;
typedef long long ll;

int uf[100005];
vector<int> w[100005];
int n,m;

int find(int x){
	if(uf[x]<0)return x;
	return uf[x]=find(uf[x]);
}

void join(int x, int y){
	x=find(x);y=find(y);
	if(x==y)return;
	n--;
	if(uf[x]>uf[y])swap(x,y);
	uf[x]+=uf[y];
	uf[y]=x;
}

int main(){
	memset(uf,-1,sizeof(uf));
	scanf("%d%d",&n,&m);
	fore(i,0,n){
		int k;
		scanf("%d",&k);
		while(k--){
			int x;
			scanf("%d",&x);x--;
			w[x].pb(i);
		}
	}
	fore(i,0,m)fore(j,0,SZ(w[i])-1)join(w[i][j],w[i][j+1]);
	puts(n==1?"YES":"NO");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:38:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
./Main.cpp:41:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&k);
                 ^
./Main.cpp:44:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&x);x--;
                  ^

Judge Result