From 906f7a493ca7eba9e5ffe15d12f23662875c9984 Mon Sep 17 00:00:00 2001
From: Exzrgs <s.nakao0120@gmail.com>
Date: Wed, 2 Oct 2024 00:49:36 +0900
Subject: [PATCH 1/2] complete

---
 .../step1.py                                  | 30 +++++++++++++++++++
 .../step2.py                                  | 28 +++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 NeetCode/letter-combinations-of-a-phone-number/step1.py
 create mode 100644 NeetCode/letter-combinations-of-a-phone-number/step2.py

diff --git a/NeetCode/letter-combinations-of-a-phone-number/step1.py b/NeetCode/letter-combinations-of-a-phone-number/step1.py
new file mode 100644
index 0000000..050f954
--- /dev/null
+++ b/NeetCode/letter-combinations-of-a-phone-number/step1.py
@@ -0,0 +1,30 @@
+class Solution:
+    def letterCombinations(self, digits: str) -> List[str]:
+        if not digits:
+            return []
+
+        digits_to_letters = {
+            "2": "abc",
+            "3": "def",
+            "4": "ghi",
+            "5": "jkl",
+            "6": "mno",
+            "7": "pqrs",
+            "8": "tuv",
+            "9": "wxyz",
+        }
+        res = []
+        combs = []
+        
+        def dfs(index):
+            if index == len(digits):
+                res.append("".join(combs))
+                return
+            
+            for c in digits_to_letters[digits[index]]:
+                combs.append(c)
+                dfs(index + 1)
+                combs.pop()
+        
+        dfs(0)
+        return res
diff --git a/NeetCode/letter-combinations-of-a-phone-number/step2.py b/NeetCode/letter-combinations-of-a-phone-number/step2.py
new file mode 100644
index 0000000..d828fb2
--- /dev/null
+++ b/NeetCode/letter-combinations-of-a-phone-number/step2.py
@@ -0,0 +1,28 @@
+class Solution:
+    def letterCombinations(self, digits: str) -> List[str]:
+        digits_to_letters = {
+            "2": "abc",
+            "3": "def",
+            "4": "ghi",
+            "5": "jkl",
+            "6": "mno",
+            "7": "pqrs",
+            "8": "tuv",
+            "9": "wxyz",
+        }
+        res = []
+        combs = []
+        
+        def dfs(index):
+            if index == len(digits):
+                res.append("".join(combs))
+                return
+            
+            for c in digits_to_letters[digits[index]]:
+                combs.append(c)
+                dfs(index + 1)
+                combs.pop()
+        
+        if digits:
+            dfs(0)
+        return res

From b2df71c4a16c5b2a1ce76e9fa14bf5cefea4b67c Mon Sep 17 00:00:00 2001
From: Exzrgs <s.nakao0120@gmail.com>
Date: Wed, 2 Oct 2024 00:57:45 +0900
Subject: [PATCH 2/2] fix

---
 NeetCode/letter-combinations-of-a-phone-number/step2.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/NeetCode/letter-combinations-of-a-phone-number/step2.py b/NeetCode/letter-combinations-of-a-phone-number/step2.py
index d828fb2..a86f8b0 100644
--- a/NeetCode/letter-combinations-of-a-phone-number/step2.py
+++ b/NeetCode/letter-combinations-of-a-phone-number/step2.py
@@ -1,6 +1,6 @@
 class Solution:
     def letterCombinations(self, digits: str) -> List[str]:
-        digits_to_letters = {
+        digit_to_letters = {
             "2": "abc",
             "3": "def",
             "4": "ghi",
@@ -18,7 +18,7 @@ def dfs(index):
                 res.append("".join(combs))
                 return
             
-            for c in digits_to_letters[digits[index]]:
+            for c in digit_to_letters[digits[index]]:
                 combs.append(c)
                 dfs(index + 1)
                 combs.pop()