Submission #992532

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int N, M;
int f[100001];
int A[100001];
bool use[100001];

int find(int u)
{
    if(u!=f[u])
        f[u]=find(f[u]);
    return f[u];
}

int main()
{
    scanf("%d%d", &N, &M);
    for(int i=1; i<=M; i++)
        f[i]=i;
    int root=0;
    for(int i=0; i<N; i++)
    {
        int K;
        scanf("%d", &K);
        for(int j=0; j<K; j++)
        {
            scanf("%d", A+j);
            use[A[j]]=true;
            root=A[j];
            if(j>0)
                f[find(A[j-1])]=find(A[j]);
        }
    }
    bool ok=true;
    for(int i=1; i<=M; i++) if(use[i])
        ok&=find(i)==find(root);
    printf(ok?"YES\n":"NO\n");
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:19:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &N, &M);
                          ^
./Main.cpp:26:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &K);
                        ^
./Main.cpp:29:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", A+j);
                             ^

Judge Result