Given an integer array nums, find a subarray that has the largest product, and return the product.
The test cases are generated so that the answer will fit in a 32-bit integer.
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.
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.
class Solution:
def maxProduct(self, nums: List[int]) -> int:
if not nums:
return 0
max_so_far = min_so_far = global_max = nums[0]
for i in range(1, len(nums)):
temp = max_so_far
max_so_far = max(nums[i], max_so_far * nums[i], min_so_far * nums[i])
min_so_far = min(nums[i], temp * nums[i], min_so_far * nums[i])
global_max = max(global_max, max_so_far)
return global_maxO(n): We traverse the array once, updating our running products and global maximum in constant time for each element.
O(1): The space usage is constant as we're only using a few variables to keep track of the current maximum and minimum products and the global maximum.