제출 #1145746

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1145746		Ekber_Ekber	Fountain (eJOI20_fountain)	C++20	0 / 100	92 ms	26948 KiB

fountain

#include <bits/stdc++.h>
#define GOOD_LUCK ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define int long long
#define itn int
#define endl "\n"
#define ff first
#define ss second
#define pb push_back
#define ppb pop_back
#define ins insert
#define lb lower_bound
#define ub upper_bound
#define bs binary_search
#define count1 __builtin_popcount
#define all(v) v.begin(), v.end()
using namespace std;

struct point{
	
};

int ctoi(char x) {
	return (int)x - '0';
}

int sumab(int a, int b) {
	return (a + b) * (b - a + 1) / 2;
}

int gcd(int a, int b) {
	if (b == 0) return a;
	return gcd(b, a%b);
}

int lcm(int a, int b) {
	return a / gcd(a, b) * b;
}

void print(vector <int> &v) {
	for (const int &i : v) cout << i << ' ';
}

constexpr int MAX = 1e+5 + 3, INF = 2e+9, MOD = 16714589, K = 18;

int temp, temp1, temp2, temp3;
vector <int> g;
pair<int, int> up[K+3][MAX];

void _() {
	int n, q;
	cin >> n >> q;
	vector <int> v(n+1), dia(n+1);
	for (int i=1; i <= n; i++) {
		cin >> dia[i] >> v[i];
	}
	v[0] = dia[0] = INF;
	g.assign(n+1, 0);
	
	// build tree
	// O(n * log(n))
	multiset <pair<int, int>> ms;
	ms.ins({dia[1], 1});
	for (int i=2; i <= n; i++) {
		while (!ms.empty()) {
			auto b = *ms.begin();
			if (b.ff < dia[i]) {
				g[b.ss] = i;
				ms.erase(ms.find(b));
			}
			else break;
		}
		ms.ins({dia[i], i});
	}
	while (!ms.empty()) {
		auto b = *ms.begin();
		if (b.ff < dia[0]) {
			g[b.ss] = 0;
			ms.erase(ms.find(b));
		}
		else break;
	}
	// correct
	
	// build up
	// O(n + n * log(n))
	for (int i=1; i <= n; i++) {
		up[0][i] = {g[i], v[i]};
	}
	for (int i=1; i <= K; i++) {
		for (int j=1; j <= n; j++) {
			up[i][j].ss = up[i-1][j].ss + up[i-1][up[i-1][j].ff].ss;
			up[i][j].ff = up[i-1][up[i-1][j].ff].ff;
			if (up[i][j].ff == 0) {
				for (int z=i+1; z <= K; z++) {
					up[z][j].ss = INF;
				}
				break;
			}
		}
	}
	// correct
	
	// queries
	// O(q * log(n))
	while (q--) {
		int x, y;
		cin >> x >> y;
		for (int i=K; i >= 0; i--) {
			if (up[i][x].ss == y) {
				for (int j=i-1; j >= 0; j--) {
					x = up[i][x].ff;
				}
				y = 0;
//				cout << "<" << i << ">";
				break;
			}
			else if (up[i][x].ss < y && up[i][x].ss != 0) {
				y -= up[i][x].ss;
				x = up[i][x].ff;
//				cout << "Minus: " << i << ' ' << up[i][x].ss << endl;
			}
//			cout << x << endl;
		}
		cout << x << endl;
	}
}

signed main() {

	GOOD_LUCK

	int tests=1;
//	cin >> tests;
	while (tests--) {
		_();
//    	cout << endl;
	}

	return 0;
}
// Problem X
// by Ekber_Ekber
/*
8 6
3 5
4 3
2 2
1 3
3 8
5 10
4 5
7 30
4 10
1 3
7 35
6 38
5 8
2 50


8 1
3 5
4 3
2 2
1 3
3 8
5 10
4 5
7 30
7 35

*/

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40