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:

a) 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.

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

Answer 1

#include <stdio.h>

int Q7a(int Q7_input) {
   int result = 0;
   while(Q7_input>0){
      result *= 10;
      result += (Q7_input%10);
      Q7_input /= 10;
   }
   return result;
}

int main(){
   int n;
   printf("Enter value for n: ");
   scanf("%d",&n);
   printf("Reverse: %d\n",Q7a(n));
   return 0;
}

int Q7a(int Q7_input) {
   int result = 0;
   while(Q7_input>0){
      result *= 10;
      result += (Q7_input%10);
      Q7_input /= 10;
   }
   return result;
}