static void Main(string[] args)
{
/*
* Given an integer array nums, find the contiguous subarray (containing at least one number)
* which has the largest sum and return its sum.
* 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.
*
* 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
*
* Example 3:
* Input: nums = [0]
* Output: 0
*
* Example 4:
* Input: nums = [-1]
* Output: -1
*
* Example 5:
* Input: nums = [-2147483647]
* Output: -2147483647
*
* Constraints:
*
* 1 <= nums.length <= 2 * 104
* -231 <= nums[i] <= 231 - 1
*/
int[] nums1 = { -2, 1, -3, 4, -1, 2, 1, -5, 4 };
int res1 = Solution1.MaxSubArray(nums1);
int[] nums2 = { -1, 2, 3, -5, 4 };
int res2 = Solution2.MaxSubArray(nums2);
int[] nums3 = { 1 };
int res3 = Solution2.MaxSubArray(nums3);
}
public static int helper(int[] nums, int left, int right)
{
if (left == right)
{
return(nums[left]);
}
int p = (left + right) / 2;
int leftSum = helper(nums, left, p);
int rightSum = helper(nums, p + 1, right);
int crossSum = Solution1.crossSum(nums, left, right, p);
int result = Math.Max(Math.Max(leftSum, rightSum), crossSum);
return(result);
}