Submission #1004896

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004896		cpdreamer	Race (IOI11_race)	C++17	0 / 100	2 ms	13144 KiB

race

#include "race.h"
#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;
vector<pair<int, int>> adj[300005];
int dp[300005][105];

void dfs(int node, int parent, int K) {
    dp[node][0] = 0;  // Distance to self with 0 jumps is 0
    for (auto &edge : adj[node]) {
        int next = edge.first;
        int length = edge.second;
        if (next == parent) continue;
        
        dfs(next, node, K);

        for (int j = K; j >= 0; --j) {
            if (dp[node][j] == INF) continue;

            for (int l = 1; l + j <= K; ++l) {
                if (dp[next][l] != INF) {
                    dp[node][j + l] = min(dp[node][j + l], dp[node][j] + dp[next][l] + length);
                }
            }
        }
    }
}

int best_path(int N, int K, int H[][2], int L[]) {
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j <= K; ++j) {
            dp[i][j] = INF;
        }
    }

    for (int i = 0; i < N - 1; ++i) {
        int u = H[i][0];
        int v = H[i][1];
        int len = L[i];
        adj[u].push_back({v, len});
        adj[v].push_back({u, len});
    }

    dfs(0, -1, K);

    int answer = INF;
    for (int i = 0; i < N; ++i) {
        answer = min(answer, dp[i][K]);
    }

    return (answer == INF) ? -1 : answer;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57