Leetcode (easy heap)

703 数据流中的第K大元素

class KthLargest{ int size; private PriorityQueue<Integer> q; public KthLargest(int k,int[] nums){ size = k; q = new PriorityQueue(k); for(int num:nums) add(num); } public int add(int val){ if(q.size()<size) q.add(val); else if(q.peek()<val){ q.poll(); q.add(val); } return q.peek(); } }

1046 最后一块石头的重量

class Solution { public int lastStoneWeight(int[] stones) { PriorityQueue<Integer> queue = new PriorityQueue<>((o1, o2) -> (o2 - o1)); for (int i = 0; i < stones.length; i++) { queue.offer(stones[i]); } while( queue.size() > 1 ) { int y = queue.poll(); int x = queue.poll(); int diff = y - x; if ( diff != 0 ) queue.offer(diff); } if ( queue.size() == 0 ) return 0; return queue.peek(); } }