Submission #1024987

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024987		dosts	Race (IOI11_race)	C++17	100 / 100	287 ms	79184 KiB

race

#include "race.h"
//Dost SEFEROĞLU
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " << 
#define vi vector<int>
#define all(xx) xx.begin(),xx.end()
#define ps(xxx) cout << (xxx) << endl;
const int LIM = 2e5+1,inf = 1e18;
vector<pii> edges[LIM];

map<int,int> s[LIM];
int ans = inf;
int k;
void dfs(int node,int p,int d = 0,int dep = 0) {
  for (auto it : edges[node]) if (it.ss != p) dfs(it.ss,node,d+it.ff,dep+1);
  s[node][d] = dep;
  for (auto it : edges[node]) {
    if (it.ss == p) continue;
    if (s[it.ss].size() > s[node].size()) s[it.ss].swap(s[node]);
    for (auto it : s[it.ss]) {
      if (s[node].count(k+2*d-it.ff)) {
        ans = min(ans,it.ss+s[node][k+2*d-it.ff]-2*dep);
      }
    }

    for (auto it : s[it.ss]) {
      if (s[node].count(it.ff)) s[node][it.ff] = min(s[node][it.ff],it.ss);
      else s[node][it.ff] = it.ss;
      if (it.ff == k+d) {
        ans = min(ans,it.ss-dep);
      }
    }
    s[it.ss].clear();
  }
}


int32_t best_path(int32_t N, int32_t K, int32_t H[][2], int32_t L[])
{
  k = K;
  for (int i=0;i<N-1;i++) {
    edges[H[i][0]].push_back({L[i],H[i][1]});
    edges[H[i][1]].push_back({L[i],H[i][0]});
  }
  dfs(0,0);
  if (ans == inf) return -1;
  return ans;
}

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