LeetCode-Maximum Subarray

题目：https://oj.leetcode.com/problems/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.

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分析：经典题，见《编程之美》

源码：Java版本
算法分析：时间复杂度O(n)，空间复杂度O(1)

public class Solution {
    public int maxSubArray(int[] A) {
        if(A==null || A.length==0) {
            return 0;
        }
        int n=A.length;
        int maxStart=A[n-1];
        int maxValue=A[n-1];
        for(int i=n-2;i>=0;i--) {
            maxStart=Math.max(A[i],A[i]+maxStart);
            maxValue=Math.max(maxStart,maxValue);
        }
        return maxValue;
    }
}