152. Maximum Product Subarray java solutions

Find the contiguous subarray within an array (containing at least one number) which has the largest product.

For example, given the array [2,3,-2,4],
the contiguous subarray [2,3] has the largest product = 6.

记录当前最大, 最小值. 因为遇到负数时, 与最小值的乘积可能成为最大值.

public class Solution {
    public int maxProduct(int[] nums) {
        if(nums == null || nums.length < 1) return 0;
        int ans = nums[0];
        int max = nums[0], min = nums[0];
        for(int i = 1; i < nums.length; i++){
            int tmp1 = max*nums[i];
            int tmp2 = min*nums[i];
            max = Math.max(nums[i],Math.max(tmp1,tmp2));
            min = Math.min(nums[i],Math.min(tmp1,tmp2));
            ans = Math.max(max,ans);
        }
        return ans;
    }
}