Given an integer array arr, return the maximum sum obtainable from any contiguous subarray (of at least one element) within arr.
Example 1
Input: [2, -1, 3, -4, 5, -2, 6]
Output: 12
Explanation: The subarray [2, -1, 3, -4, 5, -2, 6] has the largest sum 12.
Example 2
Input: [-5, -2, -3, -1]
Output: -1
Explanation: The subarray [-1] has the largest sum -1.
Example 3
Input: [7]
Output: 7
Explanation: The subarray [7] has the largest sum 7.
Constraints
Case 1
Input: [0, -2, 3, 5, -1, 2]
Expected: 9
Case 2
Input: [-10, 2, 3, -2, 4, -1]
Expected: 7
Case 3
Input: [1, 2, 3, 4, 5]
Expected: 15
Case 4
Input: [-3, -2, -1, -4]
Expected: -1
Case 5
Input: [4, -1, 2, 1, -5, 4]
Expected: 6