53. Maximum Subarray

Maximum Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [-2,1,-3,4,-1,2,1,-5,4], the contiguous subarray [4,-1,2,1] has the largest sum = 6.

click to show more practice.

More practice:

If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

Solution

public class Solution {
   public int maxSubArray(int[] nums) {
        int max = Integer.MIN_VALUE;
        int runner = 0;

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

            if (max < runner) {
                max = runner;
            }

            if (runner < 0)
                runner = 0;
        }

        return max;
    }
}