LeetCode 152. Product maximum subarray daily question

Problem description

Give you an array of integers nums , Please find the non empty continuous subarray with the largest product in the array （ The subarray contains at least one number ）, And returns the product of the subarray .

The answer to the test case is  32- position Integers .

Subarray Is a continuous subsequence of an array .

Example 1:

Input : nums = [2,3,-2,4]
Output : 6
explain :  Subarray [2,3] There is a maximum product 6.
Example 2:

Input : nums = [-2,0,-1]
Output : 0
explain :  The result can't be 2, because [-2,-1] It's not a subarray .
 

Tips :

1 <= nums.length <= 2 * 104
-10 <= nums[i] <= 10
nums The product of any prefix or suffix of Guarantee   It's a 32- position Integers

source ： Power button （LeetCode）
link ：https://leetcode.cn/problems/maximum-product-subarray
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Java

class Solution {
    public int maxProduct(int[] nums) {
        if(nums.length == 1) return nums[0];
        int ans = 0;
        int positive = 1;
        int negative = 1;

        for(int n : nums){
            if(positive <= 0) positive = 1;
            if(negative >= 0) negative = 1;

            if(n < 0){
                int t = negative;
                negative = positive * n;
                positive = t * n;
            }else {
                negative *= n;
                positive *= n;
            }
            if(positive > ans) ans = positive;
        }
        return ans;
    }
}