Submission #704606

#	Time	Username	Problem	Language	Result	Execution time	Memory
704606		thrasherr_1	Fountain (eJOI20_fountain)	C++17	100 / 100	295 ms	47788 KiB

fountain

#include <bits/stdc++.h>
using namespace std ;

#define ff first
#define ss second
#define ll long long
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define ones(x) __builtin_popcount(x)
#define remove(v)  v.erase(unique(all(v)), v.end())
#define rep(i, a, b) for(int i = a; i <= b; i++)
#define per(i, a, b) for(int i = a; i >= b; i--)

#ifdef local
#include "C:\debug.h"
#else
#define dbg(x...) 42
#endif

#define int ll

const int N = 1e5 + 2 ;

int n , q , d[N] , c[N] , up[N][19] , sum[N][19] , used[N] ;
vector<int> g[N] ;

void dfs(int v , int p) {
    used[v] = 1 ;
    rep(i , 1 , 18) {
        up[v][i] = up[up[v][i - 1]][i - 1] ;
        sum[v][i] = sum[v][i - 1] + sum[up[v][i - 1]][i - 1] ;
    }
    for(auto & to : g[v]) {
        if(to != p) {
            dfs(to , v) ;
        }
    }
}

void solve(){
    cin >> n >> q ;
    rep(i , 1 , n) {
        cin >> d[i] >> c[i] ;
    }
    stack<pair<int,int>> s ;
    rep(i , 1 , n) {
        sum[i][0] = c[i] ;
        while(sz(s) && s.top().first < d[i]) {
            up[s.top().second][0] = i ;
            g[i].pb(s.top().second) ;
            s.pop() ;
        }
        s.push({d[i] , i}) ;
    }
    rep(j , 0 , 18) sum[n + 1][j] = INT_MAX ;
    rep(i , 1 , n) if(!up[i][0]) up[i][0] = n + 1 ;
    per(i , n , 1) {
        if(!used[i]) {
            dfs(i , i) ;
        }
    }
    rep(i , 1 , q) {
        int ind , k ; cin >> ind >> k ;
        per(j , 18 , 0) {
            if(k > sum[ind][j]) {
                k -= sum[ind][j] ;
                ind = up[ind][j] ;
            }
        }
        if(ind > n) ind = 0 ;
        cout << ind << "\n" ;
    }
    
}

signed main () {
	ios::sync_with_stdio(false) ;
	cin.tie(0) ;
	int test = 1 ;
	// cin >> test ; 
	for(int i = 1 ; i <= test ; i++) {
		solve() ;
	}
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40