Двоичный поиск

int BinarySearch (int A[], int Lb, int Ub, int Key)
{

int M;
while(1)
{

M = (Lb + Ub)/2;
if (Key < A[M])

Ub = M - 1;

else
if (Key > A[M])

Lb = M + 1;

else

return M;

if (Lb > Ub)

return -1;

}

}

void main()
{

srand(time(NULL));
const long SIZE=10;
int ar[SIZE];
int key,ind;

// до сортировки
for(int i=0;i<SIZE;i++)
{

ar[i]=rand()%100;
cout<<ar[i]<<"\t";

}
cout<<"\n\n";
cout<<"Enter any digit:";
cin>>key;
ind=BinarySearch(ar,0,SIZE,key);
cout<<"Index - "<<ind<<"\t";
cout<<"\n\n";

}