C#实现二分法查找算法

2022-11-30 12:51:35

/// <summary>
/// 二分法查找
/// </summary>
/// <param name="arr"></param>
/// <param name="key">要查找的对象</param>
public static int BinarySearch(int[] arr,int value)
{
int low = 0;
int high = arr.Length - 1;
while(low<=high)
{
int middle = (low + high) / 2;
if (value == arr[middle])
{
return middle;//如果找到了就直接返回这个元素的索引
}
else if(value >arr[middle])
{
low = middle + 1;
}
else
{
high = middle - 1;
}
}
return -1;//如果找不到就返回-1；
}