数据结构与算法读书笔记5----C# 二叉查找

//<summary>
//二叉查找       

//<param name="value">数字</param> 

//</summary>       

//<returns>int</returns>

public static int BinSearch(int[] arr,int value)
{
            int upperBound, lowerBound, searchNumber;
            lowerBound = 0;
            upperBound = arr.Length - 1;
            while (lowerBound <= upperBound)
            {
                searchNumber = (upperBound + lowerBound) / 2;
                if (arr[searchNumber] == value)
                {
                    return searchNumber;
                }
                else
                {
                    if (value < arr[searchNumber])
                    {
                        upperBound = searchNumber - 1;
                    }
                    else
                    {
                        lowerBound = searchNumber + 1;
                    }
                }
            }
            return -1;
 }