Example $1$:

Input: nums $=[-2,1,-3,4,-1,2,1,-5,4]$

Output: $6$

Explanation: The subarray $4,-1,2,1$ has the largest sum $6.$

Example $2$:

Input: nums $=[1]$

Output: $1$

Explanation: The subarray $[1]$ has the largest sum $1.$

Example $3$:

Input: nums $=[5,4,-1,7,8]$

Output: $23$

Explanation: The subarray $5,4,-1,7,8$ has the largest sum $23.$

Constraints:

$1$ nums. length $<msup\; id="EditorElement\_3231917"><mrow><mn\; id="EditorElement\_3231909">1</mn><mn\; id="EditorElement\_3231910">0</mn></mrow><mrow\; id="EditorElement\_3231916"><mn\; id="EditorElement\_3231913">5</mn></mrow></msup>$

$-{10}^4$ nums $[i]{10}^4$

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.