Even & Odd Number Checker Program Also Give Its Factorial – C Language

#include <stdio.h>
#include <stdlib.h>
int add();
int main()
{
add();

return 0;
}
int add()
{
int c,d,a,b=1,i;
printf(“Enter a number\n”);
scanf(“%d”,&a);
if(a%2==0){
printf(“The number is even and its factorial cant be calculated\n”);
}
else{
for(i=1;i<=a;i++){
b=b*i;
}
printf(“The factorial of a number is %d\n”,b);
}
}