C, C++, C#, VB.net, Java is not a big deal, key lies in logic

/* Basic C Program (covers pgm. to find factorial, fibnacci, prime, armstrong, even, leap, pyramid, reverse number, sum of digits of a number )- concentrate in logic */

#include<stdio.h>
#include<conio.h>

void factorial(int a);
void fibnacci(int b);
void prime(int c);
void armstrong(int d);
void even(int e);
void leap(int f);
void pyramid(int g);
void revnum(int h);
void sumofdigits(int i);

void main(){
int num;
clrscr();
printf("\n Enter the number: ");
scanf("%d",&num);
factorial(num);
fibnacci(num);
prime(num);
armstrong(num);
even(num);
leap(num);
pyramid(num);
revnum(num);
sumofdigits(num);
getch();
}

void factorial(int a)
{
int i,fact=1;
for(i=1;i<=a;i++)
  {
fact=fact*i;
  }printf("\n The factorial of %d is: %d",a,fact);
 }

void fibnacci(int b)
{
int x=0,y=1,z,i;
for(i=0;i<b;i++)
{
z=x+y;
printf("\n %d",x);
x=y;
y=z;}
}

void prime(int c)
{
int i,s=0;
for(i=1;i<=c;i++)
{
if((c%i)==0)
s=s+1;
}
if(s==2)
{printf("\n %d is a prime number",c);}
else
printf("\n %d is not a prime number",c);
}

void armstrong(int d)
{
int r,sum=0,t;
t=d;
while(d!=0)
{
r=d%10;
sum=sum+(r*r*r);
d=d/10;
}
if(t==sum){
printf("\n %d is armstrong number",t);}
else
printf("\n %d is not an armstrong number",t);
}

void even(int e)
{
if((e%2)==0){
printf("\n %d is even number",e);
}
else
printf("\n %d is not an even number",e);
}

void leap(int f)
{
if((f%4)==0 && (f%100)!=0||(f%400)==0){
printf("\n %d is a leap year",f);
}
else
printf("\n %d is not a leap year",f);
}

void pyramid(int g)
{
int i,j;
printf("\n The pyramid for %d is:\n",g);
for(i=1;i<=g;i++)
{
for(j=1;j<=i;j++)
{
printf("%d",j);
}
printf("\n");
}
for(i=g;i>1;i--)
{
for(j=1;j<i;j++)
{
printf("%d",j);}
printf("\n");
}}

void revnum(int h)
{
int r,sum=0,t;
t=h;
while(h!=0)
{
r=h%10;
sum=(sum*10)+r;
h=h/10;}
printf("\n The reverse of %d is: %d",t,sum);
}

void sumofdigits(int i)
{
int r,sum=0,t;
t=i;
while(i!=0)
{
r=i%10;
sum=sum+r;
i=i/10;
}
printf("\n The sum of digits of %d is: %d",t,sum);}

OUTPUT

Here number= 12(say)