Submission #589288

#	Time	Username	Problem	Language	Result	Execution time	Memory
589288		jasmin	Wells (CEOI21_wells)	C++14	0 / 100	1 ms	212 KiB

wells

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

struct graph{
    vector<vector<int> > adi;
    vector<int> depth;

    graph(int n){
        adi.resize(n);
        depth.resize(n);
    }

    bool dfs(int v, int p, int k, int d){

        bool pos=true;
        depth[v]=0;
        for(auto u: adi[v]){
            if(u==p) continue;

            pos=pos && dfs(u, v, k, (d+1)%k);
            if(d!=0 && min(depth[v], k-d)+min(depth[u], k-d)+1>=k){
                pos=false;
            }
            depth[v]=max(depth[v], depth[u]);
        }

        depth[v]++;
        return pos;
    }
};

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, k;
    cin >> n >> k;
    graph g(n);
    for(int i=0; i<n-1; i++){
        int a, b;
        cin >> a >> b;
        g.adi[a-1].push_back(b-1);
        g.adi[b-1].push_back(a-1);
    }

    bool pos=false;
    for(int i=0; i<n; i++){
        if(g.dfs(i, -1, k, 0)){
            pos=true;
        }
    }

    if(pos){
        cout << "YES\n";
    }
    else{
        cout << "NO\n";
    }
    cout << 0 << "\n";
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 30