골드바흐의 추측

https://www.acmicpc.net/problem/6588

6588번: 골드바흐의 추측

// 코드

import java.util.*;
import java.io.*;
 
public class Main{
  public static void main(String[] args) throws Exception {
 
    // Please Enter Your Code Here
    BufferedWriter bw  = new BufferedWriter(new OutputStreamWriter(System.out));
    BufferedReader br  = new BufferedReader(new InputStreamReader(System.in));
    
    int max = 1000000;
    int[] isPrime = new int[max+1];
    
    for(int i=2; i<=max; i++) {
      for(int j=i*2; j<=max; j+=i) {
        if(isPrime[j] == 0) isPrime[j] = 1;
      }
    }
    
    boolean flag = false;
    while(true) {
      
      int n = Integer.parseInt(br.readLine());
      if(n==0) break;
      
      for(int i=2; i<=n/2; i++) {
        if(isPrime[i] == 0 && isPrime[n-i] == 0) {
          bw.write(n + " = " + i + " + " + (n-i));
          bw.newLine();
          flag = true;
          break;
        }
      }
      
      if(!flag) {
        bw.write("Goldbach's conjecture is wrong.");
        bw.newLine();
      }
      
    }
        
    br.close();
    bw.flush();
    bw.close();
    
  }
}