#include<stdio.h>
void display(long int n);
void Rdisplay(long int n);
int sumdigits( long int n);
main( )
{
long int num;
printf("Enter number : ");
scanf("%ld", &num);
printf("%d\n",sumdigits(num));
printf("\n");
display(num);
printf("\n");
Rdisplay(num);
printf("\n");
}/*End of main()*/
/*Finds the sum of digits of an integer*/
int sumdigits(long int n)
{
if( n/10 == 0 ) /* if n is a single digit number*/
return n;
return n%10 + sumdigits(n/10);
}/*End of sumdigits()*/
/*Displays the digits of an integer*/
void display(long int n)
{
if( n/10==0 )
{
printf("%d",n);
return;
}
display(n/10);
printf("%d",n%10);
}/*End of display()*/
/*Displays the digits of an integer in reverse order*/
void Rdisplay(long int n)
{
if(n/10==0)
{
printf("%d",n);
return;
}
printf("%d",n%10);
Rdisplay(n/10);
}/*End of Rdisplay()*/
Enter number : 10
1
10
01
Press any key to continue . . .
First understand the algorithm carefully. Then study the program line-by-line and compare it with the output. Finally, review the explanation section to strengthen your logic and programming understanding.
Rewrite the program without looking at the code. Modify values, conditions or logic and run it again. This helps improve confidence and strengthens coding skills much faster.