You are given an array of integers (both positive and negative). Find the contiguous sequence with the largest sum. Return the 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.