LeetCode: 784 solved

Author: devMEremenko

Python/LeetCode/784. Letter Case Permutation.py

@@ -0,0 +1,29 @@
+# https://leetcode.com/problems/letter-case-permutation/
+
+class Solution:
+    
+    # Time O(2^n)
+    # Space O((2^n)*n)
+    # Where n is a number of characters in a string
+    def letterCasePermutation(self, s: str) -> [str]:
+        res = []
+        
+        for c in s:
+            if not res:
+                if c.isdigit():
+                    res.append([c])
+                else:
+                    res.append([c.lower()])
+                    res.append([c.upper()])
+            else:
+                for idx in range(len(res)):
+                    lower = res[idx]
+                    if c.isdigit():
+                        lower.append(c)
+                    else:
+                        upper = [item for item in lower]
+                        lower.append(c.lower())
+                        upper.append(c.upper())
+                        res.append(upper)
+                        
+        return [''.join(item) for item in res]