算法原型---求数组中子数组和最大的值

num在遍历数组过程中表示遍历到当前位置子数组和的最大值

public class Main {
	public static void main(String[] args) {
		int[] a = new int[8];
		a[0] = 3;
		a[1] = -2;
		a[2] = 1;
		a[3] = -6;
		a[4] = 3;
		a[5] = 2;
		a[6] = -1;
		a[7] = 3;
		System.out.println(res(a));
	}

	public static int res(int[] a) {
		if(a == null || a.length <= 0)
			return 0;
		int num = a[0];
		int cur = a[0];
		for (int i = 1; i < a.length; i++) {
			cur = cur < 0 ? 0 : cur;
			cur += a[i];
			num = Math.max(num, cur);
		}
		return num;
	}
}