CONVERSION OF DECIMAL TO BINARY

/*convert decimal to binary */
#include<stdio.h>
#include<conio.h>
void main()
{
int a=1,rem,bin=0,num;
clrscr();
printf("Enter decimal number :");
scanf("%d",&num);
while(num>0)
{
rem=num%2;
bin+=(rem*a);
num/=2;
a*=10;
}
printf("binary =%d",bin);
getch();
}

CONVERSION OF BINARY TO DECIMAL

/*convert binary to decimal */
#include<stdio.h>
#include<conio.h>
void main()
{
int j=1,dec=0,d,n,rem;
clrscr();
printf("Enter a binary number :");
scanf("%d",&n);
while(n>0)
{
rem=n%10;
d=rem*j;
dec+=d;
j*=2;
n/=10;
}
printf("decimal number is = %d",dec);
getch();
}

PRODUCT OF DIGITS

 /*find the product of digits */
 #include<stdio.h>
 #include<conio.h>
 void main()
 {
int rem,prod=1,n;
clrscr();
printf("Enter a integer :");
scanf("%d",&n);
while(n>0)
{
rem=n%10;
prod*=rem;
n/=10;
}
printf("factorial %d",prod);
getch();
 }

FACTORIAL : (Example 2)

/*find the factorial using funtion calling */
#include<stdio.h>
#include<conio.h>
long int fact(int);
void main()
{
int n;
long int a;
clrscr();
printf("Enter a number :");
scanf("%d",&n);
a=fact(n);
printf("factorial %ld ",a);
getch();


}
long int fact(int n)
{
if(n==0)
return (1);
else
return (n*fact(n-1));
}

FACTORIAL : (Example 1)

/*find the factorial  of a number */
#include<stdio.h>
#include<conio.h>
void main()
{
int n,num;
long fact=1;
clrscr();
printf("Enter the number :");
scanf("%d",&n);
num=n;
if(n<0)
printf("No factorial of -ve number \n");
else
{
while(n>1)
{
fact*=n;
n--;
}
printf("factorial of %d =%ld",num,fact);
}
getch();
}

Leap Year: (Example 2) This program checks whether year is a leap year ...

/* program to find whether a year is leap or not */
#include<stdio.h>
#include<conio.h>
void main()
{
int year;
printf("Enter year :");
scanf("%d",&year);
if(year%100==0)
{
if(year%400==0)
printf("Leap year \n");
else
printf("Not leap year \n");
}
else
{
if(year%4==0)
printf("Leap year \n");
else
printf("Not leap year \n");
}
getch();
}

Leap Year: (Example 1)C program to check if a given year is leap year or...

/*find a year is lear or not */
#include<stdio.h>
#include<conio.h>
void main()
{
int year;
clrscr();
printf("Enter a year : ");
scanf("%d",&year);
if(year%4==0 &&(year%100!=0 || year%400==0))
printf("This is leap year ");
else
printf("This is not leap year ");
getch();
}