题解

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

const int MAX_N = 2e5+10;

struct Item {
	int q;  
	int t; 
	int x; 
	int n; 

	bool operator<(const Item &y) {
		if (x - t == y.x - y.t) { return q > y.q; }
		return x - t < y.x - y.t;
	}
} p[MAX_N];

int main() {
	int N;
	map<int, int> pts;  
	cin >> N;
	for (int i = 0; i < N; i++) { cin >> p[i].q >> p[i].t >> p[i].x >> p[i].n; }

	sort(p, p + N);

	int ans = 0;
	for (int i = 0; i < N; i++) {
		if (p[i].q == 2) {
			pts[p[i].x + p[i].t] += p[i].n;
		} else {
			int n = p[i].n;
			while (n) {
				map<int, int>::iterator it = pts.lower_bound(p[i].x + p[i].t);

				if (it == pts.end()) break;
				int u = min(n, it->second);

				if (u == it->second) {
					pts.erase(it);
				} else {
					it->second -= u;
				}

				n -= u;
				ans += u;
			}
		}
	}

	cout << ans << endl;
}