Submission #1831886

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Source Code Expand

# include <bits/stdc++.h>

# define fr first
# define sc second
# define ll unsigned long long
# define mk make_pair
# define pb emplace_back
# define sz(s) (int)s.size()
# define all(s) s.begin(), s.end()

using namespace std;

const int N = 2e5+10;
const int inf = 1e9+7;

int n, m, p[N], sz[N];
vector <int> v[N];

int f_s(int a) {
    return (p[a] == a) ? a : p[a] = f_s(p[a]);
}

void un_s(int a, int b) {
    a = f_s(a);
    b = f_s(b);
    if(a != b) {
        sz[a] += sz[b];
        p[b] = a;
    }
}

int main () {
    scanf("%d%d", &n, &m);
    for(int i = 1, k; i <= n; i++) {
        scanf("%d", &k);
        for(int j = 1, x; j <= k; j++) {
            scanf("%d", &x);
            v[x].pb(i);
        }
        p[i] = i, sz[i] = 1;
    }
    for(int i = 1; i <= m; i++) {
        if(sz(v[i]) == 0) continue;
        for(int j = 1; j < sz(v[i]); j++)
            un_s(v[i][j - 1], v[i][j]);
    }
    if(sz[f_s(1)] < n) puts("NO");
    else puts("YES");
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:33:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
                          ^
./Main.cpp:35:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &k);
                        ^
./Main.cpp:37:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &x);
                            ^

Judge Result