- Maximum Product Subarray #270

Author: ayosecu

maximum-product-subarray/ayosecu.py

@@ -0,0 +1,30 @@
+from typing import List
+
+class Solution:
+    """
+        - Time Complexity: O(n), n = len(nums)
+        - Space Complexity: O(1)
+    """
+    def maxProduct(self, nums: List[int]) -> int:
+        max_now, max_prod, min_prod = nums[0], nums[0], nums[0]
+        
+        for num in nums[1:]:
+            if num < 0:
+                # if number is negative, swap the min/max value
+                max_prod, min_prod = min_prod, max_prod          
+
+            max_prod = max(num, max_prod * num)
+            min_prod = min(num, min_prod * num)
+            max_now = max(max_now, max_prod)          
+        
+        return max_now
+    
+tc = [
+        ([2,3,-2,4], 6),
+        ([-2,0,-1], 0)
+]
+
+sol = Solution()
+for i, (n, e) in enumerate(tc, 1):
+    r = sol.maxProduct(n)
+    print(f"TC {i} is Passed!" if r == e else f"TC {i} is Failed! - Expected: {e}, Result: {r}")