## Description

Hello Everyone..

Welcome to lapmos.com

Today we write a program in c , that how to calculate the given number is prime of not. Before start the code , we know about the prime number ( What is prime number ?)

**Prime Number : **Prime number is a number which divisible by 1 and own so we called the number is prime. The condition is number is greater than 1. or other words, A number is divisble by itself or 1 so called the prime number.

So now let's Start the code...

**Logic 1**

```
#include<stdio.h>
int main()
{
int n;
printf("Enter the number : ");
scanf("%d", &n);
int count = 0;
if(n==1){
count = 1;
}
for(int i=2; i<n; i++){
if(n%i==0){
count++;
}
}
if(count==0){
printf("%d is prime", n);
}
else{
printf("%d is not prime", n);
}
return 0;
}
```

**Output :**

Enter the number : 7

7 is prime

**Logic 2**

```
``````
#include<stdio.h>
int main()
{
int n;
printf("Enter the number : ");
scanf("%d", &n);
int count = 0;
int flag = 0;
if(n==1){
flag = 1;
}
for(int i=2; i<=n/2; i++){
if(n%i==0){
flag = 1;
}else{
count++;
}
}
if(flag==0){
printf("%d is prime", n);
}
else{
printf("%d is not prime", n);
}
return 0;
}
```

**Output :**

Enter the number : 1

1 is not prime

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