Non-Decreasing Subsequences

Find all increasing (non-decreasing) subsequences of length at least 2 from an integer array. Subsequences preserve the original order but may skip elements. A subsequence is non-decreasing if each element is greater than or equal to the previous one. Return all unique such subsequences.

Examples
Input: [4,6,7,7]
Output: [[4,6],[4,6,7],[4,6,7,7],[4,7],[4,7,7],[6,7],[6,7,7],[7,7]]
Hints

Non-Decreasing Subsequences

Find all increasing (non-decreasing) subsequences of length at least 2 from an integer array. Subsequences preserve the original order but may skip elements. A subsequence is non-decreasing if each element is greater than or equal to the previous one. Return all unique such subsequences.