<p>Given an integer array <code>nums</code>, return <em>all the different possible non-decreasing subsequences of the given array with at least two elements</em>. You may return the answer in <strong>any order</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [4,6,7,7]
<strong>Output:</strong> [[4,6],[4,6,7],[4,6,7,7],[4,7],[4,7,7],[6,7],[6,7,7],[7,7]]
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [4,4,3,2,1]
<strong>Output:</strong> [[4,4]]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 15</code></li>
	<li><code>-100 &lt;= nums[i] &lt;= 100</code></li>
</ul>

class Solution:
    def findSubsequences(self, nums: list[int]) -> list[list[int]]:
        n = len(nums)
        result = set()
        seq = []

        def dfs(index: int):
            if index == n:
                if len(seq) >= 2:
                    result.add(tuple(seq))
                return

            if not seq or seq[-1] <= nums[index]:
                seq.append(nums[index])
                dfs(index + 1)
                seq.pop()

            dfs(index + 1)

        dfs(0)
        return result


sol = Solution()
print(sol.findSubsequences([4, 6, 7, 7]))

24900