找出给定数数组里连续的元素和的最大值

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication4
{
class Program
{
static void Main(string[] args)
{
FindMaxAmountValue rr = new FindMaxAmountValue();
// Random r = new Random();

int[] list=new int[]{-22,-11, 0, 0,0,0};
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
int maxTotalValue=0;
rr.FindMaxA(list,out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] {0, 0, 0, 0 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] { -22, -33, -1, -10 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] { 22, -33, -100, -10 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] { 22, -33, -100, -10, 19, 18, 13, 25, 21 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] { -22, -33, -100, -10, 19, 18, 13, 25, 21 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);

list = new int[] { 22, -33, -100, -10, 19, 18, 13, 25, 21, -21 };
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
maxTotalValue = 0;
rr.FindMaxA(list, out maxTotalValue);
Console.WriteLine("got subTotal: {0}", maxTotalValue);
}

}

public class FindMaxAmountValue
{

/// <summary>
/// 找出它们的规律；
/// 1. 当没有正数时，只需要比较单个元素，它就是最大值
/// 2. 当有正数时， 需要相加，但是每次加后，标记出最大值；并且若和为0或者负数时，总和清零；继续计算后面的。
/// 时间复杂度是Q（n）。

/// </summary>
/// <param name="list"></param>
/// <param name="maxTotalValue"></param>
/// <returns>true, that means, that is max sum, otherwise, no max sum value.</returns>
public bool FindMaxA(int[] list, out int maxTotalValue)
{
maxTotalValue = Int32.MinValue;
int len = list.Length;
if (list == null || len <= 0) return false; // not can't find its maximum value.

//1. check if none of them in the list are positive --------------
int i = 0;
for (; i < len;i++ )
{
if (list[i] > 0)
{
break;
}
else
{
if (list[i] > maxTotalValue)
{
maxTotalValue = list[i];
}
}
}

// there is not any positive number in the list, return it.
if (i == len)
{
return true;
}

// 2. There are positive number in the list, handle it --------------------------
// we know the list[i] is greater than 0.

int currentMaxTotalValue = 0;
for (; i < len;i++ )
{
currentMaxTotalValue = currentMaxTotalValue + list[i];
if(currentMaxTotalValue>maxTotalValue)
{
maxTotalValue = currentMaxTotalValue;
}

if (currentMaxTotalValue < 0)
{
currentMaxTotalValue = 0;
}
}

return true;
}
}
}