LeetCode - Split Array into Consecutive Subsequences

Question Definition

You are given an integer array sorted in ascending order (may contain duplicates), you need to split them into several subsequences, where each subsequences consist of at least 3 consecutive integers. Return whether you can make such a split. Example 1:

Input: [1,2,3,3,4,5]
Output: True
Explanation:
You can split them into two consecutive subsequences :
1, 2, 3
3, 4, 5

Example 2:

Input: [1,2,3,3,4,4,5,5]
Output: True
Explanation:
You can split them into two consecutive subsequences :
1, 2, 3, 4, 5
3, 4, 5

Example 3:

Input: [1,2,3,4,4,5]
Output: False

Note:

1. The length of the input is in range of [1, 10000]

   Java Solution

   class Solution {
    private HashMap<Integer, PriorityQueue<Integer>> dmap;
    public boolean isPossible(int[] nums) {
        dmap = new HashMap<>();
        for (int num : nums) {
            PriorityQueue<Integer> pq0 = getOrPut(num - 1);
            int len = pq0.isEmpty() ? 0 : pq0.poll();
            PriorityQueue<Integer> pq1 = getOrPut(num);
            pq1.offer(len + 1);
        }
        for (int key : dmap.keySet()) {
            for (int len : dmap.get(key)) {
                if (len < 3) return false;
            }
        }
        return true;
    }
    public PriorityQueue<Integer> getOrPut(int num) {
        PriorityQueue<Integer> pq = dmap.get(num);
        if (pq == null) {
            pq = new PriorityQueue<Integer>();
            dmap.put(num, pq);
        }
        return pq;
    }
   }