# PriorityQueue  - LC


%[Link]
**#1 https://leetcode.com/problems/sort-integers-by-the-power-value/**

		class Solution {
		     int help(int x) {
				if (x == 1) {
				    return 1;
				}
				int total = 0;
				while (x != 1) {
				    if (x % 2 == 0) {
					x = x / 2;
					++total;
				    } else {
					x = 3 * x + 1;
					++total;
				    }
				}
				return total;
		    }
			public int getKth(int lo, int hi, int k) {
				PriorityQueue<int[]> queue = new PriorityQueue<>(
					(a, b) -> a[1] == b[1] ? a[0] - b[0] : a[1] - b[1]);

				for (int i = lo; i <= hi; i++) {
				    int[] arr = new int[]{i, help(i)};
				    queue.add(arr);
				}
				while (k > 1) {
				    queue.poll();
				    --k;
				}

				return queue.peek()[0];
		    }		

> 
#2 https://leetcode.com/problems/queue-reconstruction-by-height/submissions/


		   class Solution {
			    public int[][] reconstructQueue(int[][] people) {
				 if (people == null || people.length == 0 || 
                      people[0].length == 0)
				    return new int[0][0];
					
			       PriorityQueue<int[]> queue = new PriorityQueue<>(
				   (a,b) -> a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]);
			       
			       for(int[] curr : people) {
				            queue.add(curr);
			       }
			       
			       List<int[]> result = new ArrayList<>();
			       while(!queue.isEmpty()) {
				             int[] person = queue.poll();
				             result.add(person[1], person);    
			       }
			       
			       return result.toArray(new int[people.length][2]);
			    }
			}