Common data structure Java definition

Summarize some common data structures encountered in the process of brushing LeetCode, and use Java to define
 
 
1. Stack

Deque<Integer> stack = new ArrayDeque<Integer>();

2. Queue

Queue<Integer> queue = new LinkedList<Integer>();

3. Small top pile

PriorityQueue<Integer> pq = new PriorityQueue<Integer>();

4. Large bank

PriorityQueue<Integer> pq = new PriorityQueue<Integer>(new Comparator<Integer>() {
    
    
			@Override
			public int compare(Integer a, Integer b){
    
    
				return b - a;	//大顶堆：参数2-参数1；小顶堆：参数1-参数2
			}
		});

5. Map

Map<Integer, Integer> map = new HashMap<Integer, Integer>();

6. Array

List<Integer> list = new ArrayList<Integer>();

7. Hash set

Set<Integer> set = new HashSet<Integer>();