二分查找递归和非递归实现

非递归实现：

int BinSearch(int data[], int length, int key)
{
if ( data == NULL || length <= 0)
throw new std::exception("Invalid Parameters");
int start = 0;
int end = length - 1;
int mid = start;
while(start <= end)
{
mid = (start + end) << 1;
if( data(mid) > key )
start = mid + 1;
else if( data(mid) < key)
end = mid - 1;
}
return mid;
}

递归实现：

int BinSearch(int data[],int length, int start, int end, int key )
{
if ( data == NULL || start <= 0 || end >= length)
throw new std::exception("Invalid Parameters");
if( start < = end )
mid = (start + end) << 1;
if ( data[mid] < key)
return BinSearch(data, length,start, mid-1, key);
else if ( data[mid] > key)
return BinSearch(data, length,mid + 1, end, key);
}