제출 #1317697

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1317697		ElayV13	경주 (Race) (IOI11_race)	C++20	0 / 100	2 ms	332 KiB

race

#include "race.h"
#include "bits/stdc++.h"
using namespace std;

const int N = 200001;
const int INF = 1e9;

vector < pair < int , int > > G[N];
map < pair < int , int > , int > mp;
map < pair < int , int > , bool > can;
vector < pair < int , pair < int , int > > > anc[N];
void add_edge(int u,int v,int w){
   G[u].push_back({v , w});
   G[v].push_back({u , w});
}
int sub[N];
bool is_rmv[N];

int gsz(int v , int p){
   sub[v] = 1;
   for(pair < int , int > nxt : G[v]){
      int u = nxt.first;
      if(u == p or is_rmv[u]) continue;
      sub[v] += gsz(u , v);
   }
   return sub[v];
}
int find_centro(int v , int p , int need){
   for(pair < int , int > nxt : G[v])
   {
      int u = nxt.first;
      if(u == p or is_rmv[u] or sub[u] <= need / 2) continue;
      return find_centro(u , v , need);
   }
   return v;
}
void dfs(int v , int p , int centro , int nd , int wd)
{
   anc[v].push_back({centro , {wd , nd}});
   if(!can[{centro , wd}]) mp[{centro , wd}] = INF;
   mp[{centro , wd}] = min(mp[{centro , wd}] , nd);
   can[{centro , wd}] = 1;
   for(pair < int , int > nxt : G[v])
   {
      int u = nxt.first;
      if(u != p && !is_rmv[u]) dfs(u , v , centro , nd + 1 , wd + nxt.second);
   }
}
void build(int v)
{
   int comp_sz = gsz(v , -1);
   int centro = find_centro(v , -1 , comp_sz);
   is_rmv[centro] = 1;
   dfs(centro , -1 , centro , 0 , 0);
   for(pair < int , int > nxt : G[centro]){
      int u = nxt.first;
      if(!is_rmv[u]) build(u);
   }
}
int get(int v , int k)
{
   int ans = INF;
   for(pair < int , pair < int , int > > nxt : anc[v])
   {
      int centro = nxt.first;
      int wg = nxt.second.first;
      int ng = nxt.second.second;
      int need = k - wg;
      if(!can[{centro , need}]) continue;
      ans = min(ans , mp[{centro , need}] + ng);
   }
   return ans;
}

int best_path(int N , int K , int H[][2] , int L[])
{
   for(int i = 0;i < N - 1;i++) add_edge(H[i][0] , H[i][1] , L[i]);
   build(0);
   int ans = INF;
   for(int i = 0;i < N;i++) ans = min(ans , get(i , K));
   if(ans == INF) ans = -1;
   return ans;
}

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