给定一个数组arr,返回子数组的最大累加和

解题思路】cur累加成为负数清零重新累加，max记录cur的最大值

public class MaxSum {

    public static int maxSum(int[] arr) {
        int max = Integer.MIN_VALUE;
        int cur = 0;
        for (int i = 0; i < arr.length; i++) {
            cur = cur + arr[i];
            max = Math.max(max, cur);
            if (cur < 0) {
                cur = 0;
            }
        }
        return max;
    }


     public static void main(String[] args) {
        int[] arr1= {3, -5, 3, -1, 2, 2, 3};
        int maxSum1 = maxSum(arr1);
        int[] arr2 = {-3, -2, -5, -1, -4};
        int maxSum2 = maxSum(arr2);
    }
}