L53. Maximum Subarray

array dp

Problem:

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.

Solution:

public int maxSubArray(int[] nums){
    if(nums == null || nums.length == 0) return 0;
    int cur = nums[0];
    int max = cur;
    
    for(int i = 0; i < nums.length; i++){
        if(cur > 0) cur += nums[i];
        else if cur = nums[i];
        max = Math.max(cur, max);
    }
    return max;
}