feat: add lc 46, 39, 78

work/1/Medium/Array/78.subsets.py

@@ -0,0 +1,50 @@
+"""
+78. Subsets
+Difficulty: Medium
+https://leetcode.com/problems/subsets/
+
+──────────────────────────────────────────────────
+
+Given an integer array nums of unique elements, return all possible
+subsets (the power set).
+
+The solution set must not contain duplicate subsets. Return the
+solution in any order.
+
+
+
+Example 1:
+
+Input: nums = [1,2,3]
+Output: [[],[1],[2],[1,2],[3],[1,3],[2,3],[1,2,3]]
+
+Example 2:
+
+Input: nums = [0]
+Output: [[],[0]]
+
+
+
+Constraints:
+
+        • 1 <= nums.length <= 10
+
+        • -10 <= nums[i] <= 10
+
+        • All the numbers of nums are unique.
+"""
+
+
+class Solution:
+    def subsets(self, nums: list[int]) -> list[list[int]]:
+        res = []
+
+        def backtrack(i, path):
+            res.append(path[:])
+            for num_idx in range(i, len(nums)):
+                path.append(nums[num_idx])
+                backtrack(num_idx + 1, path)
+                path.pop()
+
+        backtrack(0, [])
+        return res