/*

*

* Display the n'th prime.

*

*/

import java.util.Scanner; // for user input

public class problem07 {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

int numberOfPrimes; // how many primes we would like

int currentPrime = 2; // starting with 2

int counter = 0; // ordinality of the prime, starting with 0th (first)

System.out.print("Which prime would you like to find? ");

numberOfPrimes = input.nextInt();

int[] primeArray = new int[numberOfPrimes]; // an array of ints, size being how many they would like

while (counter < numberOfPrimes) { // loop ends when we've reached how many primes we want

if (isPrime(currentPrime, primeArray, counter) == true) {

System.out.println(currentPrime + " is prime.");

primeArray[counter] = currentPrime; // set our n'th array spot with the prime we've found

counter++; // now we will find the n+1'th primeu

}

currentPrime++;

}

}

// considers our candidate for primeness by testing if it's divisible by previous primes

public static boolean isPrime(int primeCandidate, int[] primeArray, int counter) {

boolean primeness = true;

for (int i = 0; i < counter; i++) { // test if candidate is a multiple of previous primes

if (primeCandidate % primeArray[i] == 0) {

primeness = false; // if it's a multiple of any previous primes, it's not prime

i=counter; // cuts our time in half by leaving the loop after candidate is found to be composite

}

}

return primeness; // otherwise it is prime

}

}