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/*Filename:P6Q06
 * Name:Wang Chaoran
Description:6 (Revising Listing 4.11, PrimeNumber.java)
Listing 4.11 determines whether a number n is prime by checking whether
2, 3, 4, 5, 6, ..., n/2 is a divisor. If a divisor is found, n is not prime.
A more efficient approach to determine whether n is prime is to check whether any
of the prime numbers less than or equal to square root  can divide n evenly. If not,
n is prime. Rewrite Listing 4.11 to display the first fifty prime numbers using this approach.
You need to use an array to store the prime numbers and later use them to check whether they are
possible divisors for n.
*/
public class P6Q06{
  public static void main(String[] args){
    int number = 2;
    int count = 0;
    int[] prime = new int[800];
    while(count<800){
      if(isPrime(number)){
        prime[count]=number;
        count++;
      }
      number++;
    }
    for(int i=0;i<prime.length;i++)
    System.out.print(prime[i]+" ");
   
  }
  static boolean isPrime(int number){
    for(int i =2;i<=Math.sqrt(number);i++){
      if(number%i==0)
        return false;
    }
    return true;
  }
  }

/*Filename:P6Q06
 * Name:Wang Chaoran
Description:6 (Revising Listing 4.11, PrimeNumber.java)
Listing 4.11 determines whether a number n is prime by checking whether
2, 3, 4, 5, 6, ..., n/2 is a divisor. If a divisor is found, n is not prime.
A more efficient approach to determine whether n is prime is to check whether any
of the prime numbers less than or equal to square root  can divide n evenly. If not,
n is prime. Rewrite Listing 4.11 to display the first fifty prime numbers using this approach.
You need to use an array to store the prime numbers and later use them to check whether they are
possible divisors for n.
*/
class P6Q06{
  public static void main(String[] args){
    int[] prime = new int[50];
    int number =2;
    int count =0;
    while(count<50){
      if(isPrime(number,count,prime))
      {
        prime[count]=number;    
        count++;
      }
     number++;
    }
    for(int i=0;i<prime.length;i++){
    System.out.print(prime[i]+" ");
    }
  }
  static boolean isPrime(int number,int count,int[] prime){
      for(int i =0;i<count;i++)
        if(number%prime[i]==0)
          return false;
    return true;  
  }
  }