Submission #1680057

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Source Code Expand

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

#define getmid(l,r) ((l) + ((r) - (l)) / 2)
#define MEM(a,b) memset(a,b,sizeof(a))
#define MP(a,b) make_pair(a,b)
#define PB push_back

typedef long long ll;
typedef pair<int,int> pii;
const double eps = 1e-8;
const int INF = (1 << 30) - 1;

vector<int> V[100010];
int fa[100010];

int Find(int x){
	return fa[x] == x ? x : fa[x] = Find(fa[x]);
}

int main(){
	int N,M;
	scanf("%d%d",&N,&M);
	for(int i = 1; i <= N; ++i){
		int K;
		scanf("%d",&K);
		for(int j = 1; j <= K; ++j){
			int a;
			scanf("%d",&a);
			V[a].PB(i);
		}
		fa[i] = i;
	}
	
	for(int i = 1; i <= M; ++i){
		if(V[i].size() == 0) continue;
		int x = Find(V[i][0]);
		for(int j = 1; j < V[i].size(); ++j){
			int y = Find(V[i][j]);
			//printf("%d %d\n",V[i][0],V[i][j]);
			if(x != y){
				fa[y] = x;
			}
		}
	}
	int num = 0;
	for(int i = 1; i <= N; ++i){
		if(fa[i] == i) num++;
	}
	if(num == 1){
		printf("YES\n");
	}
	else printf("NO\n");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:35:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&M);
                     ^
./Main.cpp:38:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&K);
                 ^
./Main.cpp:41:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a);
                  ^

Judge Result