Time: 0 ms (100%), Space: 17.7 MB (91.79%) - LeetHub

0017-letter-combinations-of-a-phone-number/0017-letter-combinations-of-a-phone-number.py

@@ -0,0 +1,26 @@
+class Solution:
+    def letterCombinations(self, digits: str) -> List[str]:
+        mapping = {
+            "2": "abc",
+            "3": "def",
+            "4": "ghi",
+            "5": "jkl",
+            "6": "mno",
+            "7": "pqrs",
+            "8": "tuv",
+            "9": "wxyz"
+        }
+
+        curr = [""]
+        next = []
+
+        for digit in digits:  
+            for prefix in curr:
+                for newChar in mapping[digit]:
+                    next.append(f"{prefix}{newChar}")
+            curr = next
+            next = []
+
+        return curr
+
+