From 6a4b03862ec502e4e5591afac73fc2dc5853dc48 Mon Sep 17 00:00:00 2001
From: E-1on <sungheon.jeong@dreamus.io>
Date: Sat, 19 Apr 2025 22:06:55 +0900
Subject: [PATCH 1/2] =?UTF-8?q?3=EC=A3=BC=EC=B0=A8.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 combination-sum/Sung-Heon.py  | 20 ++++++++++++++++++++
 decode-ways/Sung-Heon.py      | 19 +++++++++++++++++++
 maximum-subarray/Sung-Heon.py | 10 ++++++++++
 number-of-1-bits/Sung-Heon.py |  7 +++++++
 valid-palindrome/Sung-Heon.py | 24 ++++++++++++++++++++++++
 5 files changed, 80 insertions(+)
 create mode 100644 combination-sum/Sung-Heon.py
 create mode 100644 decode-ways/Sung-Heon.py
 create mode 100644 maximum-subarray/Sung-Heon.py
 create mode 100644 number-of-1-bits/Sung-Heon.py
 create mode 100644 valid-palindrome/Sung-Heon.py

diff --git a/combination-sum/Sung-Heon.py b/combination-sum/Sung-Heon.py
new file mode 100644
index 000000000..55ce74d72
--- /dev/null
+++ b/combination-sum/Sung-Heon.py
@@ -0,0 +1,20 @@
+class Solution:
+    def combinationSum(self, candidates: list[int], target: int) -> list[list[int]]:
+        result = []
+
+        def backtrack(start: int, target: int, current: list[int]):
+            if target == 0:
+                result.append(current[:])
+                return
+
+            for i in range(start, len(candidates)):
+                if candidates[i] > target:
+                    continue
+
+                current.append(candidates[i])
+                backtrack(i, target - candidates[i], current)
+                current.pop()
+
+        candidates.sort()
+        backtrack(0, target, [])
+        return result
diff --git a/decode-ways/Sung-Heon.py b/decode-ways/Sung-Heon.py
new file mode 100644
index 000000000..77ee5452d
--- /dev/null
+++ b/decode-ways/Sung-Heon.py
@@ -0,0 +1,19 @@
+class Solution:
+    def numDecodings(self, s: str) -> int:
+        if not s or s[0] == '0':
+            return 0
+
+        n = len(s)
+        dp = [0] * (n + 1)
+        dp[0] = 1
+        dp[1] = 1
+
+        for i in range(2, n + 1):
+            if s[i - 1] != '0':
+                dp[i] += dp[i - 1]
+
+            two_digit = int(s[i - 2:i])
+            if 10 <= two_digit <= 26:
+                dp[i] += dp[i - 2]
+
+        return dp[n]
\ No newline at end of file
diff --git a/maximum-subarray/Sung-Heon.py b/maximum-subarray/Sung-Heon.py
new file mode 100644
index 000000000..10e3da33f
--- /dev/null
+++ b/maximum-subarray/Sung-Heon.py
@@ -0,0 +1,10 @@
+class Solution:
+    def maxSubArray(self, nums: list[int]) -> int:
+        max_sum = nums[0]
+        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
diff --git a/number-of-1-bits/Sung-Heon.py b/number-of-1-bits/Sung-Heon.py
new file mode 100644
index 000000000..089d10d73
--- /dev/null
+++ b/number-of-1-bits/Sung-Heon.py
@@ -0,0 +1,7 @@
+class Solution:
+    def hammingWeight(self, n: int) -> int:
+        count = 0
+        while n:
+            count += n & 1
+            n >>= 1
+        return count
diff --git a/valid-palindrome/Sung-Heon.py b/valid-palindrome/Sung-Heon.py
new file mode 100644
index 000000000..6e199c767
--- /dev/null
+++ b/valid-palindrome/Sung-Heon.py
@@ -0,0 +1,24 @@
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+        filtered = ''.join(char.lower() for char in s if char.isalnum())
+        end = len(filtered) - 1
+        if end <= 0:
+            return True
+        start = 0
+        while True:
+            end_s = filtered[end]
+            start_s = filtered[start]
+            if end_s == start_s:
+                end -= 1
+                start += 1
+
+
+            else:
+                return False
+            if start >= end:
+                return True
+            if end <= 0:
+                return True
+            continue
+
+

From aa8c514611993cbb4ab126c5d1f0edfe7a4dbf3a Mon Sep 17 00:00:00 2001
From: Sung-Heon <elon4856@gmail.com>
Date: Sat, 19 Apr 2025 22:10:46 +0900
Subject: [PATCH 2/2] =?UTF-8?q?3=EC=A3=BC=EC=B0=A8.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 decode-ways/Sung-Heon.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/decode-ways/Sung-Heon.py b/decode-ways/Sung-Heon.py
index 77ee5452d..bcbb8e495 100644
--- a/decode-ways/Sung-Heon.py
+++ b/decode-ways/Sung-Heon.py
@@ -16,4 +16,4 @@ def numDecodings(self, s: str) -> int:
             if 10 <= two_digit <= 26:
                 dp[i] += dp[i - 2]
 
-        return dp[n]
\ No newline at end of file
+        return dp[n]