From b59cf2e87d85cb3ecf95d9bdbf31b6087487a51a Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 10:44:20 +0900
Subject: [PATCH 1/7] Solve : Valid Palindrome

---
 valid-palindrome/printjin-gmailcom.py | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 valid-palindrome/printjin-gmailcom.py

diff --git a/valid-palindrome/printjin-gmailcom.py b/valid-palindrome/printjin-gmailcom.py
new file mode 100644
index 000000000..58f90e78a
--- /dev/null
+++ b/valid-palindrome/printjin-gmailcom.py
@@ -0,0 +1,4 @@
+class Solution:
+    def isPalindrome(self, s):
+        cleaned = [c.lower() for c in s if c.isalnum()]
+        return cleaned == cleaned[::-1]
\ No newline at end of file

From 8076db0f2d97f52d5744218b8b1b64604bd91eca Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 10:48:38 +0900
Subject: [PATCH 2/7] Fix : Lint Error

---
 valid-palindrome/printjin-gmailcom.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/valid-palindrome/printjin-gmailcom.py b/valid-palindrome/printjin-gmailcom.py
index 58f90e78a..a58734637 100644
--- a/valid-palindrome/printjin-gmailcom.py
+++ b/valid-palindrome/printjin-gmailcom.py
@@ -1,4 +1,4 @@
 class Solution:
     def isPalindrome(self, s):
         cleaned = [c.lower() for c in s if c.isalnum()]
-        return cleaned == cleaned[::-1]
\ No newline at end of file
+        return cleaned == cleaned[::-1]

From 3a7c42b3fd10f4e2a7bf69133785a124e9481a38 Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 17:35:41 +0900
Subject: [PATCH 3/7] Solve : Number if 1 Bits

---
 number-of-1-bits/printjin-gmailcom.py | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 number-of-1-bits/printjin-gmailcom.py

diff --git a/number-of-1-bits/printjin-gmailcom.py b/number-of-1-bits/printjin-gmailcom.py
new file mode 100644
index 000000000..060b273cc
--- /dev/null
+++ b/number-of-1-bits/printjin-gmailcom.py
@@ -0,0 +1,3 @@
+class Solution:
+    def hammingWeight(self, n):
+        return bin(n).count('1')

From 791072c6fc79a66b7a37eebc0d92757449bd2dc0 Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 17:37:42 +0900
Subject: [PATCH 4/7] Refactor : Number of 1 Bits

---
 combination-sum/printjin-gmailcom.py  | 0
 number-of-1-bits/printjin-gmailcom.py | 6 +++++-
 2 files changed, 5 insertions(+), 1 deletion(-)
 create mode 100644 combination-sum/printjin-gmailcom.py

diff --git a/combination-sum/printjin-gmailcom.py b/combination-sum/printjin-gmailcom.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/number-of-1-bits/printjin-gmailcom.py b/number-of-1-bits/printjin-gmailcom.py
index 060b273cc..13a6eb9ba 100644
--- a/number-of-1-bits/printjin-gmailcom.py
+++ b/number-of-1-bits/printjin-gmailcom.py
@@ -1,3 +1,7 @@
 class Solution:
     def hammingWeight(self, n):
-        return bin(n).count('1')
+        cnt = 0
+        while n > 0:
+            cnt += n % 2
+            n //= 2
+        return cnt

From e64125a41b9e516639d2a9c2aa241fbc5dd3926a Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 17:50:30 +0900
Subject: [PATCH 5/7] Solve : Decode Ways

---
 decode-ways/printjin-gmailcom.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 decode-ways/printjin-gmailcom.py

diff --git a/decode-ways/printjin-gmailcom.py b/decode-ways/printjin-gmailcom.py
new file mode 100644
index 000000000..ffec156e3
--- /dev/null
+++ b/decode-ways/printjin-gmailcom.py
@@ -0,0 +1,13 @@
+class Solution:
+    def numDecodings(self, s):
+        if not s:
+            return 0
+        dp = [0] * (len(s) + 1)
+        dp[0] = 1 
+        dp[1] = 1 if s[0] != '0' else 0 
+        for i in range(2, len(s) + 1):
+            if '1' <= s[i - 1] <= '9':
+                dp[i] += dp[i - 1]
+            if '10' <= s[i - 2:i] <= '26':
+                dp[i] += dp[i - 2]
+        return dp[len(s)]  

From 6a2d333bce99ed8092eb6ab451bf379a228ba01d Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 18:13:45 +0900
Subject: [PATCH 6/7] Solve : Maximum Subarray

---
 maximum-subarray/printjin-gmailcom.py | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 maximum-subarray/printjin-gmailcom.py

diff --git a/maximum-subarray/printjin-gmailcom.py b/maximum-subarray/printjin-gmailcom.py
new file mode 100644
index 000000000..4e420ab67
--- /dev/null
+++ b/maximum-subarray/printjin-gmailcom.py
@@ -0,0 +1,7 @@
+class Solution:
+    def maxSubArray(self, nums):
+        max_sum = current_sum = nums[0]
+        for num in nums[1:]:
+            current_sum = max(num, current_sum + num)
+            max_sum = max(max_sum, current_sum)
+        return max_sum

From ae107c86f54c5d5bbde4f1705d8d707c3635f8a4 Mon Sep 17 00:00:00 2001
From: printjin <printjin@gmail.com>
Date: Sun, 13 Apr 2025 18:18:26 +0900
Subject: [PATCH 7/7] Solve : Combination Sum

---
 combination-sum/printjin-gmailcom.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/combination-sum/printjin-gmailcom.py b/combination-sum/printjin-gmailcom.py
index e69de29bb..94afe2604 100644
--- a/combination-sum/printjin-gmailcom.py
+++ b/combination-sum/printjin-gmailcom.py
@@ -0,0 +1,15 @@
+class Solution:
+    def combinationSum(self, candidates, target):
+        output, nums = [], []
+        def dfs(start, total):
+            if total > target:
+                return
+            if total == target:
+                return output.append(nums[:])
+            for i in range(start, len(candidates)):
+                num = candidates[i]
+                nums.append(num)
+                dfs(i, total + num)
+                nums.pop()
+        dfs(0, 0)
+        return output