Question

A prime number is a method that is evenly divisible by only itslef and 1. Write a method called isPrime, which takes only one integer as an argument and returns true if the number is prime or false if the number is not prime. Create a method to store a list of all the prime numbers from 1 to 100 in a file called Primes.txt. Use the package primes; at the beginning of your code and be sure to document your program with your name.

Answer 1

For checking Number is prime or not

#include<stdio.h>

#include<conio.h>

void main(){

int a,check;

clrscr();/*for clear screen*/

printf("Enter A number :");

scanf("%d",&a);

check = isPrime(a);

if(check ==1)

{

printf("Prime number");

}

else

{

printf("Not Prime number");

}

getch();

}

int isPrime(int number)

{

int i=2;

for (i=2; i < number; i++)

{

if(number%i==0)

{

return 0;

break;

}

}

if(i==number)

{

return 1;

}

return 0;

}

For stroing between 1 to 100 prime number in prime.txt

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

void store();

int main(){

int a,check;

clrscr();/*for clear screen*/

store();

getch();

}

void store()

{

int i=2;

int j =2;

char fname[] = "prime.txt";

FILE *fp;

fp = fopen(fname,"at+");

for (i=2; i <100; i++)

{

for (j = 2; j<=i; j++)

{

if(i==j)

{

fprintf(fp,"%d\n",i);

}

else

{

if(i%j ==0){

break;

}

}

}

}

fclose(fp);

}