Submission #821825

#	Time	Username	Problem	Language	Result	Execution time	Memory
821825		nemethm	Race (IOI11_race)	C++17	21 / 100	3047 ms	11784 KiB

race

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

using namespace std;
using ll = long long int;

vector<pair<int,ll>> g[100100];

ll level[100100], dist[100100];

ll k, ans = -1;

void dfs(int node, int prev = -1){
  if(dist[node] == k){
    ans = ans == -1 ? level[node] : min(ans, level[node]);
  }
  for(auto i : g[node]){
    if(i.first != prev){
      level[i.first] = level[node] + 1;
      dist[i.first] = dist[node] + i.second;
      dfs(i.first, node);
    }
  }
}

int best_path(int N, int K, int H[][2], int L[])
{
  k = K;
  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 i = 0; i < N; ++i){
    fill(level, level + N, 0);
    fill(dist, dist + N, 0);
    dfs(i);
  }
  return ans;
}

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