Submission #1230940

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230940		zut3	Race (IOI11_race)	C++20	9 / 100	3095 ms	40004 KiB

race

#include "race.h"
#include<bits/stdc++.h>

using namespace std;

int n, k;
vector<vector<pair<int, int>>> g;
vector<map<int, int>> d;

int mn = 2e9;
bool have_ans = false;

void dfs(int v, int prev) {
    for(auto [u, w]: g[v]) {
        if(prev == u) continue;

        dfs(u, v);
        for(auto [key, val]: d[u]) {
            if(d[v].count(key+w)) {
                d[v][key+w] = min(d[v][key+w], val+1);
            } else {
                d[v][key+w] = val+1;
            }
        }
        d[v][w] = 1;
    }

    if(d[v].count(k)) {
        mn = min(mn, d[v][k]);
        have_ans = true;
    }
}

int best_path(int N, int K, int H[][2], int L[]) {
    n = N; k = K;

    g.assign(n, vector<pair<int, int>>());
    d.assign(n, map<int, int>());

    for(int i = 0; i < n-1; i++) {
        g[H[i][0]].push_back({H[i][1], L[i]});
        g[H[i][1]].push_back({H[i][0], L[i]});
    }

    for(int v = 0; v < n; v++) {
        dfs(v, -1);
        for(int i = 0; i < n; i++) g[i].clear();
    }

    if(have_ans) return mn;
    return -1;
}

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