HERE YOU GO I HAVE MADE YOU THE FIRST PROGRAM
//part A
#include <iostream.h>
int main ()
{
int digit;
cout<<"Enter the four digit number.\n";
cin>>digit;
int first = ( digit / 1000 + 7 ) % 10;
int second = ( digit % 1000 / 100 + 7 ) % 10;
int third = ( digit % 1000 % 100 / 10 + 7 ) % 10;
int fourth = ( digit % 1000 % 100 % 10 + 7 ) % 10;
int temp = first;
int temp1 = second;
int temp2 = third;
int temp3 = fourth;
//swap
temp = third;
temp1= fourth;
temp2= first;
temp3= second;
third = third * 1000;
fourth = fourth * 100;
first = first* 10;
second= second * 1;
int encrypted = third + fourth + first + second;
cout<<"Encrypted number is "<<encrypted<<endl;
return 0;
}