Submission #561571

#	Time	Username	Problem	Language	Result	Execution time	Memory
561571		piOOE	Road Closures (APIO21_roads)	C++17	0 / 100	329 ms	5076 KiB

roads

#include "roads.h"

#include <bits/stdc++.h>

using namespace std;

#define all(x) begin(x), end(x)

typedef long long ll;

const int N = 2001;
int A[N], B[N], W[N], n;
ll dp[N][2];
int k;
vector<pair<int, int>> g[N];

void dfs(int v, int p) {
    vector<pair<int, int>> adj;
    for (auto [to, w]: g[v]) {
        if (to != p) {
            dfs(to, v);
            adj.emplace_back(to, w);
        }
    }
    if (k > (int)size(adj)) {
        vector<ll> nw;
        ll ans = 0;
        for (auto [to, w]: adj) {
            ans += dp[to][0] + w;
            nw.push_back(dp[to][1] - dp[to][0] - w);
        }
        sort(all(nw));
        for (int i = 0; i < (int)size(nw); ++i) {
            if (nw[i] < 0)
                ans += nw[i];
        }
        dp[v][1] = dp[0][v] = ans;
    } else {
        {
            vector<ll> nw;
            ll ans = 0;
            for (auto [to, w]: adj) {
                ans += dp[to][0] + w;
                nw.push_back(dp[to][1] - dp[to][0] - w);
            }
            sort(all(nw));
            for (int i = 0; i < k - 1; ++i) {
                if (nw[i] < 0)
                    ans += nw[i];
            }
            dp[v][1] = ans;
        }
        {
            vector<ll> nw;
            ll ans = 0;
            for (auto [to, w]: adj) {
                ans += dp[to][0] + w;
                nw.push_back(dp[to][1] - dp[to][0] - w);
            }
            sort(all(nw));
            for (int i = 0; i < k; ++i) {
                if (nw[i] < 0)
                    ans += nw[i];
            }
            dp[v][0] = min(dp[v][1], ans);
        }
    }
}

vector<ll> minimum_closure_costs(int nn, vector<int> uu, vector<int> vv, vector<int> ww) {
    n = nn;
    for (int i = 0; i < n - 1; ++i) {
        A[i] = uu[i], B[i] = vv[i], W[i] = ww[i];
        g[A[i]].emplace_back(B[i], W[i]);
        g[B[i]].emplace_back(A[i], W[i]);
    }
    vector<ll> ans;
    for (k = 0; k < n; ++k) {
        dfs(0, -1);
        ans.push_back(dp[0][0]);
    }
    return ans;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 14
• Subtask 4: 0 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22