Submission #990182

#	Time	Username	Problem	Language	Result	Execution time	Memory
990182		hasan2006	Race (IOI11_race)	C++17	21 / 100	343 ms	39508 KiB

race

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

using namespace std;

#define TL ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define rall(s) s.rbegin(),s.rend()
#define all(s) s.begin(),s.end()
#define pb push_back
#define se second
#define fi first
#define ll long long
#define ld long double
#define YES cout<<"YES\n"
#define Yes cout<<"Yes\n"
#define yes cout<<"yes\n"
#define NO cout<<"NO\n"
#define No cout<<"No\n"
#define no cout<<"no\n"


const int N = 5e5 + 9 , mod = 1e9 + 7;
ll a[N] , b[N] , dp[N] , c[N] , d[N] , sz[N] , us[N];
vector<pair<int,int>>v[N];
int dfs_sz(int n , int par = 0){
    sz[n] = 1;
    for(auto to : v[n])
        if(!us[to.fi] && to.fi != par)
            sz[n] += dfs_sz(to.fi , n);
    return sz[n];
}
ll ans = 1e9 , k;
int get_centroid(int n , int par , int s){
    for(auto to : v[n])
        if(!us[to.fi] && to.fi != par && sz[to.fi] > s / 2)
            return get_centroid(to.fi , n , s);
    return n;
}
set<pair<ll,ll>>st,st1;
void dfs(int n , int par, ll dis  , ll cnt){
    st1.insert({dis , cnt});
    if(dis == k)
        ans = min(ans , cnt);
    auto it = st.lower_bound({k - dis , 0});
    if(it->fi == k - dis)
        ans = min(ans , cnt + it->se);
    for(auto to : v[n])
        if(!us[to.fi] && to.fi != par)
            dfs(to.fi , n , dis + to.se , cnt + 1);
}


void centroid(int n){
    int x = get_centroid(n , 0 , dfs_sz(n));
    us[x] = 1;
    st.clear();
    for(auto to : v[x]){
        if(!us[to.fi]){
            st1.clear();
            dfs(to.fi , x , to.se , 1);
            for(auto it : st1)
                st.insert(it);
        }
    }
    for(auto to : v[x])
        if(!us[to.fi])
            centroid(to.fi);
}

int best_path(int N, int K,  int H[][2], int L[]){
    k = K;
    for(int i = 0; i < N - 1; i++) {
        int x = H[i][0] + 1,y = H[i][1] + 1;
        v[x].pb({y, L[i]});
        v[y].pb({x, L[i]});
    }
    centroid(1);
    if(ans > N)
        ans = -1;
    return ans;
}
// Author : حسن

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