Submission #674552

#	Time	Username	Problem	Language	Result	Execution time	Memory
674552		Nicolas125841	Burza (COCI16_burza)	C++14	0 / 160	1 ms	340 KiB

burza

#include <bits/stdc++.h>

using namespace std;

#define YES "DA"
#define NO "NE"

vector<vector<int>> layers;
vector<bitset<20>> coverage;

bitset<20> dfs(vector<vector<int>> &mp, int n, int p, int d, int k){
    if(layers.size() == d)
        layers.push_back(vector<int>());

    if(d == k){
        coverage[n] |= 1;
        coverage[n] <<= layers[d].size();
    }

    layers[d].push_back(n);

    for(int v : mp[n]){        
        if(v != p){
            bitset<20> res = dfs(mp, v, n, d+1, k);

            if(layers.size() > k && d < k)
                coverage[n] |= res;           
        }
    }

    return coverage[n];
}

int main(){
    cin.tie(NULL)->sync_with_stdio(false);

    int n, k;
    cin >> n >> k;

    vector<vector<int>> mp(n, vector<int>());    
    coverage = vector<bitset<20>>(n, bitset<20>());

    for(int i = 0; i < n-1; i++){

        int u, v;
        cin >> u >> v;

        mp[--u].push_back(--v);
        mp[v].push_back(u);

    }
    
    dfs(mp, 0, -1, 0, k);
    
    if(layers.size() <= k)
        cout << YES << "\n";
    else{
        unordered_set<bitset<20>> cur, prev = {bitset<20>()};
        bool g = false;

        for(int i = 1; i <= k; i++){
            for(int v : layers[i]){
                for(bitset<20> bs : prev){
                    if((coverage[v] & bs) == 0){
                        cur.insert(coverage[v] | bs);

                        if((coverage[v] | bs).count() == layers[k].size())
                            g = true;
                    }
                }
            }

            swap(cur, prev);
            cur.clear();
        }

        cout << (g ? YES : NO) << "\n";
    }

    
}

Compilation message (stderr)

burza.cpp: In function 'std::bitset<20> dfs(std::vector<std::vector<int> >&, int, int, int, int)':
burza.cpp:12:22: warning: comparison of integer expressions of different signedness: 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   12 |     if(layers.size() == d)
      |        ~~~~~~~~~~~~~~^~~~
burza.cpp:26:30: warning: comparison of integer expressions of different signedness: 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   26 |             if(layers.size() > k && d < k)
      |                ~~~~~~~~~~~~~~^~~
burza.cpp: In function 'int main()':
burza.cpp:55:22: warning: comparison of integer expressions of different signedness: 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   55 |     if(layers.size() <= k)
      |        ~~~~~~~~~~~~~~^~~~

• Subtask 1: 0 / 16
• Subtask 2: 0 / 16
• Subtask 3: 0 / 16
• Subtask 4: 0 / 16
• Subtask 5: 0 / 16
• Subtask 6: 0 / 16
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• Subtask 10: 0 / 16