leetcode

commit 9fce40e7e010e496dce11e684915d7d648135538
parent 059292e8e6c05a3e3465a3df1a447e559031cdd8
Author: Andrew Laack <andrew@laack.co>
Date:   Wed, 16 Jul 2025 14:40:16 -0500

Completed letter combinations of a phone number

Diffstat:
A
letter-combinations-of-a-phone-number/letter-combinations-of-a-phone-numberV1.py
 | 
37
+++++++++++++++++++++++++++++++++++++

1 file changed, 37 insertions(+), 0 deletions(-)
diff --git a/letter-combinations-of-a-phone-number/letter-combinations-of-a-phone-numberV1.py b/letter-combinations-of-a-phone-number/letter-combinations-of-a-phone-numberV1.py
@@ -0,0 +1,37 @@
+class Solution:
+    def letterCombinations(self, digits: str) -> List[str]:
+
+        if digits == "":
+            return []
+
+        lookup = {
+            2: ["a", "b", "c"],
+            3: ["d", "e", "f"],
+            4: ["g", "h", "i"],
+            5: ["j", "k", "l"],
+            6: ["m", "n", "o"],
+            7: ["p", "q", "r", "s"],
+            8: ["t", "u", "v"],
+            9: ["w", "x", "y", "z"],
+        }
+        opts = options([], lookup, digits, 0)
+
+        final_res = ["".join(opt) for opt in opts]
+
+        return final_res
+
+
+def options(current, lookup, digits, index):
+    if index >= len(digits):
+        return [current]
+
+    current_opts = lookup[int(digits[index])]
+    ret_ls = []
+
+    for opt in current_opts:
+        ls_cp = current.copy()
+        ls_cp.append(opt)
+        results = options(ls_cp, lookup, digits, index + 1)
+        for result in results:
+            ret_ls.append(result)
+    return ret_ls