053. Maximum Subarray

/*
 * @lc app=leetcode id=53 lang=java
 *
 * [53] Maximum Subarray
 *
 * https://leetcode.com/problems/maximum-subarray/description/
 *
 * algorithms
 * Easy (42.32%)
 * Total Accepted:    440.3K
 * Total Submissions: 1M
 * Testcase Example:  '[-2,1,-3,4,-1,2,1,-5,4]'
 *
 * Given an integer array nums, find the contiguous subarray (containing at
 * least one number) which has the largest sum and return its sum.
 * 
 * Example:
 * Input: [-2,1,-3,4,-1,2,1,-5,4],
 * Output: 6
 * Explanation: [4,-1,2,1] has the largest sum = 6.
 * 
 * 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 Solution {
    public int maxSubArray(int[] nums) {
        if (nums.length == 0) {
            return 0;
        }
        
        int newsum = nums[0];
        int max = nums[0];

        for(int i = 1; i < nums.length; i++) {
            newsum = Math.max(newsum + nums[i], nums[i]);
            max = Math.max(max, newsum);
        }
        
        return max;
    }
}