PRIME NUMBER PROGRAM IN C

-
In this example , you will learn a program to check whether a given number is prime number or not.


Prime number: 

A number that is greater than 1 and can be only divided by 1 and itself, is called a prime number. In short, Prime numbers can't be divided by other numbers than itself and 1.


Example: 
2,3,5,7,11,13...... are the examples of prime numbers.

Program to check for prime number:


//check whether given number is prime or not

#include<stdio.h> 
int main( )
{
int num, i, n=0, flag=0;
printf("Enter the number :");
scanf("%d",&num);
n=num/2;

for(i=2;i<=n;i++)
{
if(num%i==0)
{
flag=1;
break;
}

if(flag==0)
printf("%d is prime number",num);
else
printf("%d is not prime number",num);

return 0;
}


Output:


Enter the number:5
5 is prime number


Enter the number:34
34 is not prime number



Note:

> 0 and 1 are not considered as prime numbers.
> 2 is the only even prime number.

__________________________________________________


Try this by your own! 
If you have any doubts feel free to drop a comment . I'll be happy to answer your questions in the comment section.
Keep coding.....


Comments

Post a Comment

Popular posts from this blog

DECIMAL TO OCTAL CONVERSION IN C

-
 In this example, you will learn a program to convert decimal number to its equivalent octal number. Decimal numbers have base 10 , and they use numbers between o to 9. while, Octal  numbers have base 8 , and they use numbers between 0 to 7. ( To understand this program , you should have prior knowledge about decimal to octal conversion. ) Program: //Program to convert decimal number to octal number #include<stdio.h> #include<conio.h> int DectoOct( int num); int main( ) { int num; printf ("Enter a decimal number:"); scanf( "%d" , &num ); printf ("%d decimal number= %d in octal number", num, DectoOct(num) ); return 0; } int DectoOct(int num) { int OctalNumber=0, i=1; while(num !=0) { OctalNumber += (num %8)*i; num /= 8; i*=10; } return OctalNumber; } Output: Enter a decimal number: 10 10 decimal number= 12 in octal number   
Read more

PROGRAM TO CONVERT BINARY CODE TO GRAY CODE

-
Image
 In this example, you will learn a program to convert the Binary code into its equivalent Gray code. (To understand this program , you should have prior knowledge about binary codes , gray codes and its conversion algorithms. ) Here are some examples of binary and its equivalent gray code: Program: //Program to Convert Binary Code to Gray Code #include<stdio.h>  int bintogray(int); int main ( ) { int bin, gray; printf ("Enter a binary number: "); scanf( "%d" , &bin ); gray = bintogray(bin); printf ("The gray code of %d is %d\n", bin, gray); return 0; } int bintogray(int bin) { int a, b, result = 0, i = 0; if (!bin) {      return 0; } else {      a = bin % 10;      bin = bin / 10;      b = bin % 10;      if ((a && !b) || (!a && b))      {          
Read more

KRISHNMURTHY NUMBER PROGRAM IN C

-
 In this example, you will learn a program to check whether entered number is Krishnamurthy number or not. Krishnamurthy Number: A krishnamurthty  number is a number whose sum of the factorial of digits is equal to the number itself.  Let's take one example: Suppose we want to check whether 40585 4! + 0! + 5! + 8! + 5! = 24 + 1 + 120 + 40320 + 120 =40585 i.e. equal to the  number itself. Hence, 40585 is a Krishnamurthy Number. Program: //Program to check whether entered number is krishnamurthy number or not. #include<stdio.h> #include<process.h> int main( ) { int i,n,a,r,c=0,s; printf (" Enter a number : "); scanf( "%d" , &n ); if(n==0) {      printf ("\n %d is not a Krishnamurthy Number.",n);        exit(0) ; } a=n; while(n>0) {      r=n%10;      s=1;      for(i=r;i>=1;i--)           s=s*i;      c=c+s;      n=n/10; } if(c==a) {      printf
Read more