Submission #939271

#	Time	Username	Problem	Language	Result	Execution time	Memory
939271		vjudge1	Chase (CEOI17_chase)	C++17	20 / 100	30 ms	3132 KiB

chase

#include <bits/stdc++.h>
#define int long long
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
using namespace std;
const int N=20;
vector <int> g[N];
int p[N];
void dfs(int v,int par){
    p[v]=par;
    for(auto to : g[v]){
        if(to!=par)dfs(to,v);
    }
}
signed main(){
    ios_base::sync_with_stdio();
    cin.tie(0);cout.tie(0);
    int n,m;
    cin>>n>>m;
    vector <int> x(n);
    for(int i=0;i<n;i++)cin>>x[i];
    for(int i=0;i<n-1;i++){
        int u,v;
        cin>>u>>v;
        u--;v--;
        g[v].pb(u);
        g[u].pb(v);
    }
    int ans=0;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++)p[j]=0;
        dfs(i,-1);
        for(int j=0;j<n;j++){
            int s=j;
            vector <int> ver;
            ver.pb(j);
            while(s!=i){
                s=p[s];
                ver.pb(s);
            }
            reverse(all(ver));
            int sz=ver.size();
            for(int mask=0;mask<(1<<sz);mask++){
                vector <int> val=x;
                int res1=0,res2=0;
                int cnt=0;
                for(int k=0;k<sz;k++){
                    if((mask & (1<<k))!=0){
                        cnt++;
                        res1+=val[ver[k]];
                        for(auto to : g[ver[k]]){
                            val[ver[k]]+=val[to];
                            val[to]=0;
                        }
                        
                    }
                    else res1+=val[ver[k]];
                    
                }
                for(int k=0;k<sz;k++){
                    res2+=val[ver[k]];
                }
                if(cnt<=m)ans=max(ans,res2-res1);
            }
            
        }
    }
    cout<<ans<<"\n";
}
/*
12 2
0 1 2 3 4 5 6 7 8 9 10 11
2 3 3 8 1 5 6 7 8 3 5  4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12
*/
           
 
           

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