250701 Touch The Sky

static class Node implements Comparable<Node> {
	long l;
	long d;
	long limit;

	Node(long l, long d) {
		this.l = l;
		this.d = d;
		this.limit = l + d;
	}

	@Override
	public int compareTo(Node o) {
		return Long.compare(this.limit, o.limit);
	}
}

public static void main(String[] args) throws Exception {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

	int n = Integer.parseInt(br.readLine());
	PriorityQueue<Node> balloons = new PriorityQueue<>();
	for (int i = 0; i < n; i++) {
		StringTokenizer st = new StringTokenizer(br.readLine());
		long l = Long.parseLong(st.nextToken());
		long d = Long.parseLong(st.nextToken());
		balloons.offer(new Node(l, d));
	}

	PriorityQueue<Long> used = new PriorityQueue<>((a, b) -> Long.compare(b, a));
	int count = 0;
	long totalHeight = 0;

	while (!balloons.isEmpty()) {
		Node current = balloons.poll();
		if (totalHeight <= current.l) {
			count++;
			totalHeight += current.d;
			used.offer(current.d);
		} else {
			long maxD = used.poll();
			long minD = Math.min(maxD, current.d);
			used.offer(minD);
			totalHeight += (minD - maxD);
		}
	}

	System.out.println(count);
}

출처:https://www.acmicpc.net/problem/15773