제출 #1335622

#제출 시각아이디문제언어결과실행 시간메모리
1335622tsengangFountain (eJOI20_fountain)C++20
100 / 100
474 ms31976 KiB
#include <bits/stdc++.h>
#define ll int
#define ff first
#define ss second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define ertunt return
using namespace std;
ll mod = 1e9+7;
vector<ll> adj[600007];
vector<ll>vis(200005);
vector<ll> f(600005), inv(600005);
ll modpow(ll a, ll b){
    ll r = 1;
    while(b){
        if(b & 1){
            r *= a;
            r %= mod;
        }
        a *= a;
        a %= mod;
        b >>= 1;
    }
    ertunt r;
}
ll nCk(ll n, ll k){
    if(k < 0 || k > n) ertunt 0;
    ertunt f[n] * inv[k] % mod * inv[n - k] % mod;
}
int main(){
	ll n,q;
	cin >> n >> q;
	vector<ll>d(n+2),c(n+2);
	d[0] = 1e9;
	c[0] = 1e9;
	for(ll i = 1; i <= n; i++){
		cin >> d[i] >> c[i];
	}
	stack<ll>s;
	s.push(0);
	vector<ll>parent(n+2);
	for(ll i = n; i >= 1; i--){
		while(d[i] >= d[s.top()]){
			s.pop();
		}
		parent[i] = s.top();
		s.push(i);
	}
	ll lg = 21;
	vector<vector<ll>>up(n+2,vector<ll>(lg+1));
	vector<vector<ll>>sum(n+2,vector<ll>(lg+1));
	for(ll i = 1; i <= n; i++){
		up[i][0] = parent[i];
		sum[i][0] = c[parent[i]];
	}
	for(ll k = 1; k <= lg; k++){
		for(ll i = 1; i <= n; i++){
			up[i][k] = up[up[i][k-1]][k-1];
			sum[i][k] = sum[i][k-1] + sum[up[i][k-1]][k-1];
		}
	}
	while(q--){
		ll r,v;
		cin >> r >> v;
		if(v <= c[r]){
			cout << r << '\n';
			continue;
		}
		v -= c[r];
		for(ll i = lg; i >= 0; i--){
			if(sum[r][i] < v){
				v -= sum[r][i];
				r = up[r][i];
			}
		}
		cout << up[r][0] << '\n';
	}
}
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