# Maximum Subarray | Leetcode

Given an integer array `nums`, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Maximum Subarray is the contiguous array with maximum sum.

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
```

Example 4:

```Input:  nums = [-2,-4,-1,-5,-7]
Output: -1
```

Constraints:

• `1 <= nums.length <= 105`
• `-104 <= nums[i] <= 104`

#### Solution

```class Solution {
public int maxSubArray(int[] nums)
{
/*If array is empty return 0*/
if(nums!= null && nums.length == 0)
{
return 0;
}

int max=nums[0],sum=0;
for(int i =0; i<nums.length; i++)
{

/* Case 1 : If sum is a negative number Say -3 and nums[i] = -2 . Assign smallest negative -2 as

Sum.
* Case 2: If sum is negative and nums[i] =1. Assign Sum = 1
*/
if(sum<nums[i] && sum<0)
{
sum = nums[i];
}
else
{
sum+= nums[i];
}
if(sum>max)
{
max = sum;
}
}
return max;
}
}
```

#### Time Complexity

Loop is running for n times so O(n) where n is the length of the array

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### Sree Hari Sanjeev

The founder of Wisdom Overflow. Software Developer at Zoho Corporation.