[LeetCode] 53. Maximum Subarray

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

For example, given the array [−2,1,−3,4,−1,2,1,−5,4],
the contiguous subarray [4,−1,2,1] has the largest sum = 6.

1. DP, but we only need to store adjacent 2 numbers.

public class Solution {
    public int maxSubArray(int[] nums) {
        int len = nums.length;
        if(0 == len)
            return 0;
        
        int pre = nums[0];
        int max = nums[0];
        
        for(int i = 1; i < len; ++i){
            if(pre < 0)
                pre = nums[i];
            else
                pre = nums[i] + pre;
            max = Math.max(max, pre);
        }

        return max;
    }
}