feat: Add solution for LeetCode problem 152

Author: WhiteHyun

maximum-product-subarray/WhiteHyun.swift

@@ -0,0 +1,38 @@
+//  
+//  152. Maximum Product Subarray
+//  https://leetcode.com/problems/maximum-product-subarray/description/
+//  Dale-Study
+//  
+//  Created by WhiteHyun on 2024/07/14.
+//  
+
+class Solution {
+  func maxProduct(_ nums: [Int]) -> Int {
+    var maxNumber = nums[0]
+    var minNumber = nums[0]
+    var answer = nums[0]
+    // Problem 190 / 191 방어 코드
+    let negativeCount = nums.filter { $0 < 0 }.count
+
+
+    for index in 1 ..< nums.count {
+      let current = nums[index]
+
+      let tempMin = minNumber
+      let tempMax = maxNumber
+
+      maxNumber = max(current, tempMin * current, tempMax * current)
+      if negativeCount > 1 {
+        minNumber = min(current, tempMin * current, tempMax * current)
+      } else {
+        minNumber = 0
+      }
+      if answer < maxNumber {
+        answer = maxNumber
+      }
+    }
+
+    return answer
+  }
+
+}