Submission #867059

#	Time	Username	Problem	Language	Result	Execution time	Memory
867059		HossamHero7	The Xana coup (BOI21_xanadu)	C++14	5 / 100	150 ms	278788 KiB

xanadu

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'
void solve(){
    int n;
    cin>>n;
    vector<vector<int>> adj(n);
    for(int i=0;i<n-1;i++){
        int a,b;
        cin>>a>>b;
        a -- , b --;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    int mask = 0;
    for(int i=0;i<n;i++){
        int x;
        cin>>x;
        if(!x) mask |= (1<<i);
    }
    queue<int> q;
    vector<int> dep((1<<n),-1);
    q.push(mask);
    dep[mask] = 0;
    while(q.size()){
        int mask = q.front();       q.pop();
        for(int i=0;i<n;i++){
            int nmask = mask ^ (1<<i);
            for(auto ch : adj[i]) nmask ^= (1<<ch);
            if(~dep[nmask]) continue;
            q.push(nmask);
            dep[nmask] = dep[mask] + 1;
        }
    }
    if(~dep[(1<<n)-1]) cout<<dep[(1<<n)-1]<<endl;
    else cout<<"impossible"<<endl;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);      cout.tie(0);
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30