53. Maximum Subarray

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Example:
Input: [-2,1,-3,4,-1,2,1,-5,4],
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.

Follow up:
If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

难度：easy

题目：
给定一整数组数，找出最大子数组计算其和并返回。

思路：包含当前元素的最大值。 MaxValueWithCurrentElement = Math.max(MaxValueWithCurrentElement + nums[i], nums[i]).然后再计算最大值。 MaxValue = Math.max(MaxValue, MaxValueWithCurrentElement)

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