Prime Number or Composite Number Example Program in C Programming Language
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number.
Example C Program to find whether a number is Prime or Composite Number
1 #include<stdio.h>
2 int main()
3 {
4 int number, counter, notprime = 0;
5
6 /*Ask the uesr to Enter a Positive Integer */
7 printf("Enter the positive integer to check for prime or composite\n");
8 scanf("%d",&number);
9
10 /*Check the remainder for zero when you divide the numbers */
11 /* if remainder is zero then it means that the number is completely divisible */
12 /* by another another and hence it can not be prime*/
13 for(counter = 2; counter <= number/2; counter++){
14 if( (number % counter) == 0 ){
15 notprime = 1;
16 break;
17 }
18 }
19
20 /* notprime == 0 means it is a prime number */
21 if(notprime == 0){
22 printf("%d is a prime number",number);
23 }else{
24 printf("%d is a composite number",number);
25 }
26 return 0;
27 }