Maximum Subarray

1. Title

Maximum Subarray

2. Http address

https://leetcode.com/problems/maximum-subarray/

3. The question

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.

4 My code(AC)

 1     public int maxSubArray(int[] nums) {
 2      
 3         if ( nums == null || nums.length == 0)
 4             return 0;
 5         int contiguousMax[] = new int[nums.length];
 6         contiguousMax[0] = nums[0];
 7         for(int i = 1 ; i < nums.length; i++)
 8         {
 9             contiguousMax[i] = Math.max(contiguousMax[i-1] + nums[i], nums[i]);
10         }
11         int opt_cur = nums[0];
12         for(int i = 1; i < nums.length; i++)
13         {
14             opt_cur = Math.max(opt_cur, contiguousMax[i]);
15         }
16         return opt_cur;
17     }
18     
19     // Accepted
20     public int maxSubArrayTwo(int[] nums) {
21         
22         if ( nums == null || nums.length == 0)
23             return 0;
24 
25         int opt_cur = nums[0];
26         int contiguousMax = nums[0];
27         for(int i = 1; i < nums.length; i++)
28         {
29             contiguousMax = Math.max(contiguousMax + nums[i], nums[i]);
30             opt_cur = Math.max(opt_cur, contiguousMax);
31         }
32         return opt_cur;
33     }