2610. Convert an Array Into a 2D Array With Conditions

```java
class Solution {
    public List<List<Integer>> findMatrix(int[] nums) {
        Map<Integer, Integer> map = new HashMap<>();
        for (int num : nums) {
            map.put(num, map.getOrDefault(num, 0)+1);
        }
        int maxCount = 0;
        for (int value : map.values()) {
            maxCount = Math.max(maxCount, value);
        }
        List[] result = new ArrayList[maxCount];
        for (int i = 0; i < maxCount; i++) {
            result[i] = new ArrayList<>();
        }
        
        for (int key : map.keySet()) {
            for (int i = 0; i < map.get(key); i++) {
                result[i].add(key);
            }
        }
        List<List<Integer>> finalResult = new ArrayList<>();
        for (int i = 0 ; i < result.length; i++) {
            finalResult.add(result[i]);
        }
        return finalResult;
    }
}
/*
T: O(n) + O(keysize()*count)
S: O(keysize()*count)

Input: nums = [1,3,4,1,2,3,1]
Output: [[1,3,4,2],[1,3],[1]]
Explanation: We can create a 2D array that contains the following rows:
- 1,3,4,2
- 1,3
- 1
All elements of nums were used, and each row of the 2D array contains distinct integers, so it is a valid answer.
It can be shown that we cannot have less than 3 rows in a valid array.

[1,3,4,1,2,3,1]

first find distinct number, use hashmap

1: 3
3: 2
4: 1
2: 1

loop hashmap to put to array

*/






```