Submission #1133467

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133467		vladilius	Chase (CEOI17_chase)	C++20	20 / 100	567 ms	172208 KiB

chase

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
const ll inf = 1e18;
const int N = 1e5;
const int K = 100;

ll dp[N + 1][K + 1][2];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, k; cin>>n>>k;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++){
        cin>>a[i];
    }
    vector<int> g[n + 1];
    for (int i = 1; i < n; i++){
        int x, y; cin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
    }
    vector<ll> s(n + 1);
    for (int i = 1; i <= n; i++){
        s[i] = a[i];
        for (int j: g[i]){
            s[i] += a[j];
        }
    }

    ll out = 0;
    function<void(int, int)> fill = [&](int v, int pr){
        for (int i: g[v]){
            if (i == pr) continue;
            fill(i, v);
        }
        for (int x = 1; x <= k; x++){
            dp[v][x][0] = dp[v][x][1] = -inf;
            for (int i: g[v]){
                if (i == pr) continue;
                dp[v][x][0] = max(dp[v][x][0], (s[v] - a[v]) + dp[i][x - 1][0] - a[v]);
                dp[v][x][0] = max(dp[v][x][0], s[v] + dp[i][x - 1][1] - a[v]);
                
                dp[v][x][1] = max(dp[v][x][1], dp[i][x][0] - a[v]);
            }
            if (x == 1) dp[v][1][0] = s[v] - a[v];

            out = max(out, dp[v][x][0]);
            out = max(out, dp[v][x][1]);
        }
    };
    
    if (n <= 1000){
        for (int i = 1; i <= n; i++){
            fill(i, 0);
        }
    }
    else {
        fill(1, 0);
    }

    cout<<out<<"\n";
}

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