Submission #1004894

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004894		cpdreamer	Race (IOI11_race)	C++14	0 / 100	1 ms	4444 KiB

race

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

#define P pair<int, int>
#define V vector
#define F first
#define S second
#define pb push_back

const int INF = 1e9;
int dp[(int)3e5][101];

void dfs(int n, int p, V<P> tree[], int k) {
    dp[n][0] = 0;  // Starting point, no steps taken, zero distance
    for (auto u : tree[n]) {
        if (u.F == p) continue;
        dfs(u.F, n, tree, k);
        for (int i = k; i >= 0; --i) {
            if (dp[n][i] == INF) continue;
            for (int j = 1; j + i <= k; ++j) {
                if (dp[u.F][j] != INF) {
                    dp[n][i + j] = min(dp[n][i + j], dp[n][i] + dp[u.F][j] + 1);
                }
            }
        }
    }
}

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;

    V<P> tree[N];
    for (int i = 0; i < N - 1; ++i) {
        tree[H[i][0]].pb({H[i][1], L[i]});
        tree[H[i][1]].pb({H[i][0], L[i]});
    }
    
    dfs(0, -1, tree, K);
    
    int ans = INF;
    for (int i = 0; i < N; ++i) {
        ans = min(ans, dp[i][K]);
    }
    return (ans == INF) ? -1 : ans;
}

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