Question

In this example you are allowed to use from the C standard library only functions for input and output (e.g. printf(), scanf())

Complete the following functions using C programming language:

1. Complete the int Q7a(intQ7_input) function takes a seven-digit positive integer as input and returns it reversed. For example, if the integer is 9806593, the program should print 3956089. You are not permitted to use any function of C standard library other than scanf()and printf().You are not permitted to use arrays either. For the case when the integer ends with 0, the number printed cannot have leading 0’s (Eg: input 3412400; output 42143).

Note: Use the division and remainder operators to separate the number into its individual digits.

2. Modify your program so it returns backwards any positive integer, not necessarily a seven-digit one.

Answer 1

I WROTE THE CODE ALONG WITH THE COMMENTS

CODE:

#include <stdio.h>
int Q7a(int Q7_input)
{
  
int digit,rev_num=0; //variables declaration.
  
while(Q7_input!=0) //condition number not equal to 0.
{
digit=Q7_input%10;
rev_num=rev_num*10+digit;
Q7_input=Q7_input/10;
}
return rev_num;
}
int main()
{
  
int num; //variable declaration.
printf("Enter seven_digit positive number: ");
scanf("%d",&num); //scan input.
  
int reverse_num=Q7a(num); //calling Q7a() funtion.
printf("Reverse number: %d",reverse_num);

return 0;
}

OUTPUT:

SCREENSHOT OF THE CODE: