Submission #531252

#	Time	Username	Problem	Language	Result	Execution time	Memory
531252		79brue	Newspapers (CEOI21_newspapers)	C++14	0 / 100	1 ms	320 KiB

newspapers

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n, m;
vector<int> link[1002];

int dfs(int x, int par = -1){
    vector<int> vec (1, 0);
    for(auto y: link[x]){
        if(y==par) continue;
        int tmp = dfs(y, x);
        vec.push_back(tmp+1);
    }

    sort(vec.rbegin(), vec.rend());
    if(par == -1){
        if(vec.size() >= 3 && vec[2] >= 2){
            puts("NO");
            exit(0);
        }
    }
    return vec[0];
}

int main(){
    scanf("%d %d", &n, &m);
    if(m!=n-1){
        puts("NO");
        return 0;
    }

    for(int i=1; i<n; i++){
        int x, y;
        scanf("%d %d", &x, &y);
        link[x].push_back(y), link[y].push_back(x);
    }

    for(int i=1; i<=n; i++){
        dfs(i);
    }

    printf("YES");
}

Compilation message (stderr)

newspapers.cpp: In function 'int main()':
newspapers.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
newspapers.cpp:37:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 8
• Subtask 3: 0 / 80