## Challenge Statement

- Given an integer array
`nums`

, find the contiguous subarray (containing at least one number) which has the largest sum and return*its sum*. - A
**subarray**is a**contiguous**part of an array. - This challenge corresponds to LeetCode #53.

### Constraints

`1 <= nums.length <= 10`

^{5}`-10`

^{4}<= nums[i] <= 10^{4}

**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 = [5, 4, -1, 7, 8]
Output: 23
```

## Solution

Below is my solution and some test cases. This solution has a **linear time complexity O(n) and a constant space complexity O(1)**, where n is the length of the input list*.*