LeetCode-in-All
152. Maximum Product Subarray
Medium
Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product, and return the product.
It is guaranteed that the answer will fit in a 32-bit integer.
A subarray is a contiguous subsequence of the array.
Example 1:
Input: nums = [2,3,-2,4]
Output: 6
Explanation: [2,3] has the largest product 6.
Example 2:
Input: nums = [-2,0,-1]
Output: 0
Explanation: The result cannot be 2, because [-2,-1] is not a subarray.
Constraints:
1 <= nums.length <= 2 * 104-10 <= nums[i] <= 10- The product of any prefix or suffix of
numsis guaranteed to fit in a 32-bit integer.
Solution
class Solution {
fun maxProduct(nums: IntArray): Int {
var pos = nums[0]
var neg = nums[0]
var max = nums[0]
for (i in 1 until nums.size) {
val temp = pos
pos = Math.max(nums[i], nums[i] * if (nums[i] >= 0) pos else neg)
neg = Math.min(nums[i], nums[i] * if (nums[i] >= 0) neg else temp)
max = Math.max(max, pos)
}
return max
}
}