Maximum_Subarray.java

/*

Given an integer array nums, find the subarray with the largest sum, and return its sum.

 

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 <= 105
-104 <= nums[i] <= 104
 

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.

*/


class Maximum_Subarray{
    public int maxSubArray(int[] nums) {
        int n = nums.length;
        int sum = nums[0];
        int best_ending = nums[0];
        for(int i = 1; i<n ; i++){
            int v1 = best_ending + nums[i];
            int v2 = nums[i];
            best_ending = Math.max(v1,v2);
            sum = Math.max(best_ending, sum) ;
            
        }
        return sum;
    }
}