53. 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.

解题思路为Dynamic Programming。

顺序扫描array，设置两个变量，一个记录到当前位置时的largest sum，一个记录以当前位置为终点的连续subarray的largest sum。

public class Solution {
    public int maxSubArray(int[] nums) {
        int maxSubArray = Integer.MIN_VALUE;
        int maxEndHere = 0;
        for(int num : nums) {
            maxEndHere = Math.max(maxEndHere + num, num);
            maxSubArray = Math.max(maxSubArray, maxEndHere);
        }
        return maxSubArray;
    }
}