PriorityQueue 顺序？

按道理pq只能保证peek是最大/最小，其他都是无序。而且poll（）完queue顺序会发生变化。
可是为什么下面这个解法的pq能一直保持poll的都是最大/最小值啊？lc621

1. class Solution {
   
2.     public int leastInterval(char[] tasks, int n) {
   
3. int intervalCount = 0;
   
4.     Map<Character, Integer> taskFrequencyMap = new HashMap<>();
   
5.     for (char chr : tasks)
   
6.       taskFrequencyMap.put(chr, taskFrequencyMap.getOrDefault(chr, 0) + 1);
   
7. 
   
8.     PriorityQueue<Map.Entry<Character, Integer>> maxHeap = new PriorityQueue<Map.Entry<Character, Integer>>(
   
9.         (e1, e2) -> e2.getValue() - e1.getValue());
   
10. 
    
11.     // add all tasks to the max heap
    
12.     maxHeap.addAll(taskFrequencyMap.entrySet());
    
13. 
    
14.     while (!maxHeap.isEmpty()) {
    
15.       List<Map.Entry<Character, Integer>> waitList = new ArrayList<>();
    
16.       int k = n + 1; // try to execute as many as 'k+1' tasks from the max-heap
    
17.       for (; k > 0 && !maxHeap.isEmpty(); k--) {
    
18.         intervalCount++;
    
19.         Map.Entry<Character, Integer> currentEntry = maxHeap.poll();
    
20.         if (currentEntry.getValue() > 1) {
    
21.           currentEntry.setValue(currentEntry.getValue() - 1);
    
22.           waitList.add(currentEntry);
    
23.         }
    
24.       }
    
25.       maxHeap.addAll(waitList); // put all the waiting list back on the heap
    
26.       if (!maxHeap.isEmpty())
    
27.         intervalCount += k; // we'll be having 'n' idle intervals for the next iteration
    
28.     }
    
29. 
    
30.     return intervalCount;
    
31.     }
    
32. }

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pq其实就是heap，poll了一个出来之后，会调整heap让下一个依旧是最大/最小的啊

PQ是每次poll完之后的peak都还是最值，不是只有第一次