PROGRAM TO FIND THE 1s COMPLEMENT OF THE ENTERED BINARY NUMBER

//PROGRAM TO FIND THE 1s COMPLEMENT OF THE ENTERED BINARY NUMBER
/*MADE BY KRISHNA AGARWAL*/
#include<iostream.h>
#include<conio.h>
#include<string.h>
class binary
{
char s[30];
public:
void read(void)
{
    cout<<"enter a binary number\n";
    cin>>s;
}
void ckh_bin(void)
{
    for(int i=0;s[i]!=0;i++)
    {
        if(s[i]!=0&&s[i]!=0)
        {
            cout<<"\nincorrect binary format....program is quit\n";
            getch();
            exit(0);
}
}
}
void ones(void)
{
    void chk_bin(); //calling member function
    for(int i=0;s[i]!=0;i++)
    {
        if(s[i]=='0')
        s[i]='1';
        else
        s[i]='0';
    }
}
void displayones(void)
{
    ones(); //calling member function
    cout<<"\nthe 1s complement of the above binary number is \n"<<s;
}
}; //class end bracket
void main()
{
    clrscr();
    binary b;
    b.read();
    b.displayones();
    getch();
}