제출 #1323794

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1323794		Trisanu_Das	경주 (Race) (IOI11_race)	C++17	0 / 100	7 ms	14392 KiB

race

#include <bits/stdc++.h>
#include "race.h"
using namespace std;
#define ff first
#define ss second

int K, ans = INT_MAX; vector<pair<int, int>> adj[200005]; set<pair<int, int>> S[200005];

void dfs(int u, int par, int dist, int depth) {
    S[u].insert({dist, depth});
    for(auto v : adj[u]){
        if(v.ff != par){
            dfs(v.ff, u, dist + v.ss, depth + 1);
            if(S[u].size() < S[v.ff].size()) swap(S[u], S[v.ff]);
            for(auto d : S[v.ff]){
                int o = K + 2 * dist - d.ff;
                auto x = S[u].lower_bound({o, -1});
                if(x != S[u].end() && (*x).ff == o)
                    ans = min(ans, d.ss + (*x).ss - 2 * depth);
            }
            for(auto d : S[v.ff]) S[u].insert(d);
        }
    }
}


int best_path(int n, int k, int h[][2], int l[]) {
    k = K;
    for (int i = 0; i < n - 1; i++){
        adj[h[i][0]].push_back({h[i][1], l[i]});
        adj[h[i][1]].push_back({h[i][0], l[i]});
    }K = k; dfs(0, 0, 0, 0); return (ans == INT_MAX) ? -1 : ans;
}

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