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.
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
Constraints:

1 <= nums.length <= 105

104 <= nums[i] <= 104
Solution:
class Solution { public int maxSubArray(int[] nums) { int max = nums[0]; for(int i=1;i<nums.length;i++){ nums[i] = Math.max(nums[i], nums[i]+nums[i1]); max = Math.max(max, nums[i]); } return max; } }
Complexity Analysis

Time complexity: $O(n)$. Only a single pass is needed.

Space complexity: $O(1)$. Only two variables are used.