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@imprakharshukla
Created February 6, 2020 17:09
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Gold Bach
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Q1_2018 {
static int n = 0;
static int primes[];
public static void main(String[] args) throws IOException {
InputStreamReader ir = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(ir);
System.out.println("Enter the Number");
n = Integer.parseInt(br.readLine());
primes = new int[n];
if (isValid()) {
oddPrimeArray();
//cycling through the array in the most efficient way to pick out all the viable combinations.
for (int i = 0; i < primes.length; ++i) {
for (int j = i; j < primes.length; ++j) {
if (primes[i] + primes[j] == n)
System.out.println(primes[i] + " " + primes[j]);
}
}
}
else
System.out.println("Invalid!");
}
static boolean isValid() {
return n > 9 && n < 50;
}
static void oddPrimeArray() {
int k = 0;
for (int i = 1; i <= n; ++i) {
int c = 0;
for (int j = 1; j <= i; ++j) {
if (i % j == 0) {
++c;
}
}
if (c == 2) {
//now checking for odd
if (i % 2 != 0) {
primes[k] = i;
++k;
}
}
}
}
}
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