折半查找

int BinarySearch(int* _array,int size, int element)
{
    int left = 0;
    int right = size-1;
    while(left< right)
    {
        int middle = (left+right)/2;

        if(element ==  _array[middle])
        {
            return middle;
        }else if(element >_array[middle])
        {
            left = middle;
        }else
        {
            right = middle;

        }
    }
    return -1 ;

}