// Program to implement Binary search
#include<iostream.h>
#include<iomanip.h>
class binarysearch
{
private:
int *x;
int items;
public:
binarysearch(int);
~binarysearch();
void input(int []);
int search(int);
};
binarysearch::binarysearch(int n)
{
items=n;
x=new int[items];
}
binarysearch::~binarysearch()
{
delete [] x;
}
void binarysearch::input(int a[])
{
for(int i=0;i<items;i++)
x[i]=a[i];
}
int binarysearch::search(int number)
{
int low=0;
int high=items-1;
int mid;
while(low<=high)
{
mid=(low+high)/2;
if(x[mid]<number)
low=mid+1;
else if(x[mid]>number)
high=mid-1;
else if(x[mid]==number)
return mid+1;
else return 0;
}
}
int main()
{
int a[100],n,temp;
cout<<" Enter how many elements \n";
cin>>n;
cout<<" Enter "<<n<<"elements in increasing order \n";
for(int i=0;i<n;i++)
cin>>a[i];
cout<<"\n Enter search number :";
cin>>temp;
binarysearch obj(n);
obj.input(a);
int position=obj.search(temp);
if(position!=0)
cout<<"\n Search number is present and its position:"<<position;
else
cout<<"\n search number is not present";
return 0;
}
Test data
Enter how many elements
8
Enter 8 elements in increasing order
12 13 16 17 20 29 56 78
Enter search number : 17
Output
Search number is present and its position :4