Backtracking-2

problem1.py

@@ -0,0 +1,25 @@
+# Space Complexity: O(h) 
+# Time Complexity: O(2 ^ n)
+
+class Solution:
+    def subsets(self, nums: List[int]) -> List[List[int]]:
+        ans = []
+
+        def rec(i,res):
+            if i >= len(nums):
+                ans.append(res[:])
+                return 
+
+
+            rec(i+1,res)
+
+            res.append(nums[i])
+            rec(i+1,res)
+            res.pop()
+
+
+        rec(0,[])
+
+        return ans
+
+

problem2.py

@@ -0,0 +1,40 @@
+# Space Complexity: O(h) -> h can max to s
+# Time Complexity: O(2^n)
+class Solution:
+    def partition(self, s: str) -> List[List[str]]:
+        def pali(s): 
+            i = 0
+            j = len(s)-1
+
+            while i <= j: 
+                if s[i] != s[j]:
+                    return False
+                i+=1
+                j-=1
+            return True
+
+        ans = []
+
+        def helper(s, pivot, path):
+            # Base Case
+            if pivot >= len(s):
+                ans.append(path[:])
+                return 
+
+            # Logic
+            for i in range(pivot, len(s)):
+                curr = s[pivot:i+1]
+                if pali(curr):
+
+                    #action
+                    path.append(curr)
+
+                    #recurse
+                    helper(s, i+1, path)
+
+                    #backtrack
+                    path.pop()
+
+
+        helper(s, 0, [])
+        return ans