Given an integer array, your task is to find all the different possible increasing subsequences of the given array, and the length of an increasing subsequence should be at least 2 .
Input: [4, 6, 7, 7]
Output: [
[4, 6],
[4, 7],
[4, 6, 7],
[4, 6, 7, 7],
[6, 7],
[6, 7, 7],
[7, 7],
[4, 7, 7],
]- The length of the given array will not exceed 15.
- The range of integer in the given array is [-100,100].
- The given array may contain duplicates, and two equal integers should also be considered as a special case of increasing sequence.