Prime number program in c using recursion




C code to check a number is prime number or not by recursion:

#include<stdio.h>

int isPrime(int,int);

int main(){

    int num,prime;

    printf("Enter a positive number: ");
    scanf("%d",&num);

    prime = isPrime(num,num/2);

   if(prime==1)
        printf("%d is a prime number",num);
   else
      printf("%d is not a prime number",num);

   return 0;
}

int isPrime(int num,int i){

    if(i==1){
        return 1;
    }else{
       if(num%i==0)
         return 0;
       else
         isPrime(num,i-1);
    }
}

Sample output:

Enter a positive number: 13
13 is a prime number

C code to check a number is prime number or not without recursion:

#include<stdio.h>

int isPrime(int);

int main(){

    int num,prime;

    printf("Enter a positive number: ");
    scanf("%d",&num);

    prime = isPrime(num);

   if(prime==1)
        printf("%d is a prime number",num);
   else
      printf("%d is not a prime number",num);

   return 0;
}

int isPrime(int num){

    int i=2;

    while(i<=num/2){
         if(num%i==0)
             return 0;
         else
             i++;
    }

    return 1;
}





Sum of n numbers using recursion in c
Matrix multiplication using recursion in c
Multiplication using recursion in c
Lcm using recursion in c
Using recursion in c find the largest element in an array
Prime number program in c using recursion
Decimal to binary conversion in c using recursion
C program for fibonacci series using recursion
Reverse a string using recursion
Write a program for palindrome using recursion
Find factorial of a number using recursion in c program
Find gcd of a number using recursion in c program
Find sum of digits of a number using recursion using cprogram
Find power of a number using recursion using c program
Binary search through recurssion using c program
Reverse a number using recursion in c program
Big list of c program examples
Post a Comment