Submission #638128

#	Time	Username	Problem	Language	Result	Execution time	Memory
638128		Iwanttobreakfree	Race (IOI11_race)	C++17	21 / 100	3056 ms	8824 KiB

race

#include "race.h"
#include <vector>
using namespace std;
int best;
void dfs(int a,int par,vector<vector<pair<int,int>>>& g,int cnt,int dist,int k){
    if(cnt>k)return;
    if(cnt==k){
        best=min(best,dist);
        return;
    }
    for(auto x:g[a]){
        if(x.first==par)continue;
        dfs(x.first,a,g,cnt+x.second,dist+1,k);
    }
}
int best_path(int N, int K, int H[][2], int L[]){
  vector<vector<pair<int,int>>> g(N,vector<pair<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]});
  }
  best=1e9;
  for(int i=0;i<N;i++)dfs(i,i,g,0,0,K);
  if(best==1e9)best=-1;
  return best;
}

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