Submission #866476

#	Time	Username	Problem	Language	Result	Execution time	Memory
866476		Irate	Race (IOI11_race)	C++14	21 / 100	3051 ms	17056 KiB

race

#include<bits/stdc++.h>
#include "race.h"
using namespace std;
const int mxN = 2e5 + 3;
vector<pair<int, int>>G[mxN];
long long depth[mxN], length[mxN];
vector<int>visited;
int K;
void dfs(int node, int par){
	for(pair<int, int>& v : G[node]){
		if(v.first != par){
			depth[v.first] = depth[node] + 1;
			length[v.first] = length[node] + v.second;
			visited.push_back(v.first);
			if(length[v.first] > K)continue;
			dfs(v.first, node);
		}
	}
}
int best_path(int n, int k, int H[][2], int L[]){
	K = k;
	for(int i = 0;i < n - 1;++i){
		int u = H[i][0], v = H[i][1];
		G[u].push_back({v, L[i]});
		G[v].push_back({u, L[i]});
	}
	long long mn = 1e18;
	for(int i = 0;i < n;++i){
		dfs(i, i);
		for(int &j : visited){
			if(length[j] == k){
				mn = min(mn, depth[j]);
			}
		}
		for(int &j : visited){
			depth[j] = 0;
			length[j] = 0;
		}
		visited.clear();
	}
	if(mn == 1e18)return -1;
	return mn;
}
// int main()
// {
// 	ios_base::sync_with_stdio(0);
// 	cin.tie(0);
// 	int n;
// 	cin >> n >> K;
// 	int H[n - 1][2], L[n - 1];
// 	for(int i = 0;i < n - 1;++i){
// 		cin >> H[i][0] >> H[i][1] >> L[i];
// 	}
// 	cout << best_path(n, K, H, L);
// }
/*
11 12
0 1 3
0 2 4 
2 3 5
3 4 4
4 5 6
0 6 3
6 7 2
6 8 5
8 9 6
8 10 7
*/

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