6-13 折半查找

int  Search_Bin(SSTable T, KeyType k)
{
    int left=1,mid,right=T.length;
    while(left<=right)
    {
        mid=(left+right)/2 ;
        if(k==T.R[mid].key) 
            return mid ;
        else if (k<T.R[mid].key )
            right=mid-1;
        else
            left=mid+1;
    }
    return 0;
}