Submission #455294

#	Time	Username	Problem	Language	Result	Execution time	Memory
455294		_Avocado_	Fountain (eJOI20_fountain)	C++14	100 / 100	627 ms	71860 KiB

fountain

#include <bits/stdc++.h>
#define int int64_t
using namespace std;

vector<vector<int>>graph, up, cap;
vector<int>c, d;
int timer = 0;
int l = 31;

void lift(int v, int par){
	up[v][0] = par;
	cap[v][0] = c[v];
	
	for(int i = 1; i<=l; ++i){
		up[v][i] = up[up[v][i-1]][i-1];
		cap[v][i] = cap[v][i-1] + cap[up[v][i-1]][i-1];
	}
	
	for(auto u: graph[v]){
		if(u != par) lift(u, v);
	}
	
}

int query(int u, int x){
	
	int cur = 0;
	
	for(int i = l; i>=0; --i){
		if(cap[u][i] + cur < x){
			cur += cap[u][i];
			u = up[u][i];
		}
		
	}
	
	return u;
}

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n, q; cin>>n>>q;
	
	up.assign(n+1, vector<int>(l+1));
	cap.assign(n+1, vector<int>(l+1));
	
	c.assign(n+1, 0);
	d.assign(n+1, 0);
	
	for(int i = 1; i<=n; ++i){
		int a, b; cin>>a>>b;
		c[i] = b;
		d[i] = a;
	}
	
	
	stack<pair<int, int>>s;
	graph.assign(n+1, vector<int>());
	vector<int>p(n+1);
	
	for(int i = 1; i<=n; ++i){
		while(!s.empty() && s.top().first < d[i]){
			p[s.top().second] = i;
			s.pop();
		}
		s.push({d[i], i});
	}
	
	while(!s.empty()){
		p[s.top().second] = 0;
		s.pop();
	}
	
	
	for(int i = 1; i<=n; ++i){
		graph[p[i]].push_back(i);
	}
	
	lift(0, 0);
	
	
	
	for(int i = 0; i<q; ++i){
		int a, b; cin>>a>>b;
		cout<<query(a, b)<<'\n';
	}
		

}

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