Adsense 728 * 15

Search

Custom Search

Program to Check whether Given Number is Prime or Not

Write a C, C++ program to check whether given number is prime or not. In this program user input one number at a time and your program prints whether the input number is prime or not.

What is Prime Number


A prime number is a number which is greater than 1 , and divisible by 1 and itself

For example -  7 is a prime number it is divisible by 1 and 7 only.

NOTE -  2 is the only even prime number. 


Logic for checking whether number is prime or not

We run a loop from 2 to num/2 and check whether the number is divisible. If the number is not divisible by any number then it's a prime number.

Program to Print all prime numbers between 1 to 100.

Print even numbers from 1 to 100.

Sorting algorithms and their time complexity.

Program to Check whether Given Number is Prime or Not


#include<iostream.h>
using namespace std;

int main(){

    int num,i,val=0;
    

    cout<<"Enter a number\n";
    cin>>num;

    /* Check whether number is divisible by number other than 1 and itself */
    for(i = 2; i <= num/2; i++){

        if(num % i == 0){
            
            val++;
            break;

        }
    }

   if(val==0)
        cout<<"Number is a prime number";
   else
      cout<<"Number is not a prime number";

   return 0;
}


C Program to Check whether Given Number is Prime or Not


#include <stdio.h>

int main(void) {
 
 int num,i,val=0;
    
    printf ("Enter a number\n");
    scanf ("%d" , &num);

    /* Check whether number is divisible by number other than 1 and itself */
    for(i = 2; i <= num/2; i++){

        if(num % i == 0){
            
            val++;
            break;

        }
    }

   if(val==0)
        printf (" The number you have input is a prime number");
   else
      printf (" The number you have input is not a prime number");
      
 return 0;
}


Output :

Enter a number :  5

The number you have input is a prime number


Enter a number : 6

The number you have input is not a prime number

No comments:

Post a Comment