Week 03 soultions

Author: HYUNAHKO

combination-sum/HYUNAHKO.py'

@@ -0,0 +1,25 @@
+class Solution:
+    def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:
+        result = []
+        
+        def backtrack(start_idx, current_combination, current_sum):
+            if current_sum == target:
+                result.append(current_combination[:]) 
+                return
+            if current_sum > target:
+                return
+            
+            # 모든 후보 탐색
+            for i in range(start_idx, len(candidates)):
+                # 현재 숫자 선택
+                current_combination.append(candidates[i])
+                
+                # 같은 숫자를 다시 사용할 수 있으므로 i부터 시작
+                backtrack(i, current_combination, current_sum + candidates[i])
+                
+                # 백트래킹
+                current_combination.pop()
+        
+        backtrack(0, [], 0)
+        return result
+        

number-of-1-bits/HYUNAHKO.py

@@ -0,0 +1,10 @@
+class Solution:
+    def hammingWeight(self, n: int) -> int:
+        result = 1
+        while (n//2 != 0):
+            remainder = n % 2
+            if (remainder==1):
+                result+=1
+            n = n//2
+        return result
+    

product-of-array-except-self/HYUNAHKO.py

@@ -37,4 +37,5 @@ def productExceptSelf(self, nums: List[int]) -> List[int]:
 
 
         return result_list
+        
 

valid-palindrome/HYUNAHKO.py

@@ -0,0 +1,12 @@
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+        s = s.lower()
+        result = [char for char in s if char.isalnum()]
+
+        n = len(result)
+        for i in range(n):
+            str1 = result[i]
+            if (str1 != result[n-i-1]):
+                return False
+        return True
+