Code Challenge: 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.

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

Example 1:

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

Example 2:

Input: nums = [-1]
Output: -1

Source: Leetcode