Submission #1150870

#	Time	Username	Problem	Language	Result	Execution time	Memory
1150870		bilgun	Newspapers (CEOI21_newspapers)	C++20	Compilation error	0 ms	0 KiB

newspapers

#include <bits/stdc++.h>
using namespace std;

long long n, m;
vector<int> g[1005];
int par[1005], path[1005];
vector<int> ans;

pair<int, int> dfs(int node, int parent) {
    int maxd = 0;
    int distm = node;
    for (auto it : g[node]) {
        if (it != parent) {
            par[it] = node;
            auto s = dfs(it, node);
            s.first++;
            if (s.first > maxd) {
                maxd = s.first;
                distm = s.second;
            }
        }
    }
    return {maxd, distm};
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m;
    
    if (m != n - 1) {
        cout << "NO";
        return 0;
    }

    for (int i = 1; i <= m; i++) {
        long long a, b;
        cin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }

    int u = dfs(1, -1).second;
    int v = dfs(u, -1).second;
    
    for( int curr = v; ; curr = par[curr]){
        h[curr] = 1;
        path[curr] = 1;
        for( auto it : g[curr]){
            h[it] = 1;
            for( auto i : g[it]){
                h[i] = 1;
            }
        }
        if( curr == u) break;
    }

    bool isUnvisited = false;
    for (int i = 1; i <= n; i++) {
        if (path[i] == 0) {
            isUnvisited = true;
            break;
        }
    }
    if (isUnvisited) {
        cout << "NO" << endl;
        return 0;
    }
    for(int i = par[v]; i != u; i = par[i]){
		ans.push_back(i);
		for(auto &j : g[i]){
			if(sz(g[j]) == 1 || path[j]) continue;
			ans.push_back(j);
			ans.push_back(i);
		}
	}
    cout << "YES" << endl;
    cout << 2 * ans.size() << endl;
    for (int x : ans) cout << x << " ";
    reverse(ans.begin(), ans.end());
    for (int x : ans) cout << x << " ";
    cout << endl;

    return 0;
}

Compilation message (stderr)

newspapers.cpp: In function 'int main()':
newspapers.cpp:48:9: error: 'h' was not declared in this scope
   48 |         h[curr] = 1;
      |         ^
newspapers.cpp:73:28: error: 'sz' was not declared in this scope
   73 |                         if(sz(g[j]) == 1 || path[j]) continue;
      |                            ^~