Example with negative
Input
nums = [2, 3, -2, 4]
Output
6
Subarray [2,3] gives product 6, which is maximal.
Full lesson preview
Find the maximum product subarray
Compute the maximum product obtainable from a contiguous subarray.
Python practice30 minArrays – Fundamentals & PatternsAdvancedLast updated March 25, 2026
Problem statement
Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest product and return that product. The array may contain positive numbers, negative numbers, and zeros. Implement an O(n) time and O(1) extra space solution.
Task
Track both maximum and minimum running products to handle negative values and zeros, returning the maximum subarray product.
Examples
Input format
Function signature: max_product_subarray(nums: list[int]) -> int
Output format
Return an integer: the maximum product of any contiguous subarray.
Constraints
1 <= len(nums) <= 10^5, -10^9 <= nums[i] <= 10^9. Expected O(n) time and O(1) space.
Samples
Sample 1
Input
nums = [-2, 0, -1]
Output
0
Maximum product achievable is 0 (single element subarray [0]).