oj.uz

Submission #998196

# Submission time Handle Problem Language Result Execution time Memory
998196 2024-06-13T11:47:27 Z MarwenElarbi Race (IOI11_race) C++17
0 / 100
 5 ms 23896 KB 
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ii pair<int,int>
const int nax=2e5+5;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<pair<int,int>> adj[nax];
int sz[nax];
bool removed[nax];
vector<vector<pair<ll,pair<ll,int>>>> dist(nax);
vector<map<int,vector<pair<int,int>>>> mp(nax);
int get_tree_size(int x,int p){
    sz[x]=1;
    for(auto u:adj[x]){
        if(u.fi==p||removed[u.fi]) continue;
        sz[x]+=get_tree_size(u.fi,x);
    }
    return sz[x];
}
int get_centroid(int x,int t_sz,int p){
    for(auto u:adj[x]){
        if(u.fi==p||removed[u.fi]) continue;
        if(sz[u.fi]*2>t_sz){
            return get_centroid(u.fi,t_sz,x);
        }
    }
    return x;
}
void get_dist(int x,int centroid,int p,pair<ll,int> cur){
    for(auto u:adj[x]){
        if(u.fi==p||removed[u.fi]) continue;
        cur.fi+=u.se;
        cur.se++;
        get_dist(u.fi,centroid,x,cur);
        cur.fi-=u.se;
        cur.se--;
    }
    //cout <<x<<" "<<centroid<<" "<<cur.fi<<" "<<cur.se<<endl;
    mp[centroid][cur.fi].pb({x,cur.se});
    dist[x].pb({centroid,cur});
}
void build(int x){
    int centroid=get_centroid(x,get_tree_size(x,-1),-1);
    for(auto u:adj[centroid]){
        if(removed[u.fi]) continue;
        get_dist(u.fi,centroid,centroid,make_pair(u.se,1));
    }
    removed[centroid]=true;
    for(auto u:adj[centroid]){
        if(removed[u.fi]) continue;
        build(u.fi);
    }
}
int n,k;
int query(int x){
    int ans=1e9;
    for(auto u:dist[x]){
        if(!u.se.fi) continue;
        for (int i = 0; i < (int)mp[u.fi][k-u.se.fi].size(); ++i)
        {
            if(mp[u.fi][k-u.se.fi][i].fi==x) continue;
            ans=min(ans,u.se.se+mp[u.fi][k-u.se.fi][i].se);
            //cout <<x<<" "<<u.fi<<" "<<ans<<endl;
        }
    }
    return ans;
}
int best_path(int N, int K, int H[][2], int L[])
{
    n=N;
    k=K;
    for (int i = 0; i < n-1; ++i)
    {
        adj[H[i][0]].pb({H[i][1],L[i]});
        adj[H[i][1]].pb({H[i][0],L[i]});
    }
    build(0);
    int ans=1e9;
    for (int i = 0; i < n; ++i)
    {
        int cur=query(i);
        ans=min(ans,cur);
    }
    return ans;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 23896 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 23896 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 23896 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 57.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 23896 KB Output isn't correct
2 Halted 0 ms 0 KB -