# Check a number is prime or not | c programing

## Check a number is prime or not

### Problem

Read a integer value, which a natural number. Find the the number is a prime number or not.

### Input

The input file contains a integer value.### Output

Print the number is a prime number or not.

### Solution

A prime number is a positive integer which is evenly divisible only by 1 and itself. Remember,

**0 &1 are not considered as prime number.**
To check the number is prime or not, we will divide the number from 2 to its half and check if it is evenly divided or not.

#include<stdio.h>

int main()

{

int i,N,flag = 0;

scanf("%d",&N);

if(N==0 || N==1){

printf("Not prime\n");

}

else{

for(i=2;i<=N/2;i++){

if(N%i == 0){

flag = 1; ///not prime

break;

}

}

if(flag == 0){

printf("prime\n");

}

else{

printf("not prime\n");

}

}

return 0;

}

int main()

{

int i,N,flag = 0;

scanf("%d",&N);

if(N==0 || N==1){

printf("Not prime\n");

}

else{

for(i=2;i<=N/2;i++){

if(N%i == 0){

flag = 1; ///not prime

break;

}

}

if(flag == 0){

printf("prime\n");

}

else{

printf("not prime\n");

}

}

return 0;

}

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