제출 #527532

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
527532		KindaNameless	경주 (Race) (IOI11_race)	C++14	21 / 100	140 ms	25356 KiB

race

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

const int lim = 200000;
vector<pair<int, int>> adj[lim + 5];
map<int, int> paths[lim + 5];
int n, k, answer = 1e9;

void dfs(int cur = 1, int par = -1){
    for(pair<int, int> ch : adj[cur]){
        if(ch.first == par)continue;

        dfs(ch.first, cur);

//        if((int)paths[ch.first].size() > (int)paths[cur].size()){
//            paths[cur].swap(paths[ch.first]);
//        }
        for(pair<int, int> elem : paths[ch.first]){
            if(paths[cur].count(k - elem.first - ch.second)){
                answer = min(answer, elem.second + 1 + paths[cur][k - elem.first - ch.second]);
            }
        }
        for(pair<int, int> elem : paths[ch.first]){
            if(elem.first + ch.second > k)continue;
            paths[cur][elem.first + ch.second] = elem.second + 1;
        }
        paths[cur][ch.second] = 1;
        paths[ch.first].clear();
    }
}

int best_path(int N, int K, int H[][2], int L[]){
    n = N; k = K;
    for(int i = 0; i < N-1; ++i){
        int u = H[i][0] + 1, v = H[i][1] + 1;
        adj[u].push_back(make_pair(v, L[i]));
        adj[v].push_back(make_pair(u, L[i]));
    }
    for(int i = 1; i <= N; ++i){
        paths[i][0] = 0;
    }

    dfs();

    return (answer == 1e9 ? -1 : answer);
}

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