求一个已知数组的最大子数组和

思路：

用textbox控件输入数组，再求出最大子数组和

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int maxsum;
            string[] strN = textBox1.Text.Split(',');
            int[] list = new int[strN.Length];
            for (int i = 0; i < strN.Length; i++)
            {
                list[i] = int.Parse(strN[i]);
            }
            maxsum = calMaxSumOfArray(list);
            textBox2.Text = maxsum.ToString();
        }
        public int calMaxSumOfArray(int[] a)//获取最大子数组和
        {
            if (null == a)
            {
                return 0;
            }
            if (a.Length == 1)
            {
                return a[0];
            }
            int sum = a[0];
            int temp = a[0];
            for (int i = 1; i < a.Length; i++)
            {
                temp = max(temp + a[i], a[i]);
                if (sum < temp)
                {
                    sum = temp;
                }
            }
            return sum;
        }
        public int max(int a, int b)
        {
            return a > b ? a : b;
        }

        private void label2_Click(object sender, EventArgs e)
        {

        }
    }
}