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.

		click to show more practice.

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