백준 2981번

원본 : www.acmicpc.net/problem/2981

2981번: 검문

 

풀이

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;

public class Main {

	public static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
	public static BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));

	public static void main(String[] args) throws Exception {
		int n = Integer.parseInt(reader.readLine());
		int arr[] = new int[n];
		int diff[] = new int[n - 1];
		
		for (int i = 0; i < n; i++) {
			arr[i] = Integer.parseInt(reader.readLine());
		}
		Arrays.sort(arr);
		for (int i = 0; i < n - 1; i++) {
			diff[i] = arr[i + 1] - arr[i];
		}
		
		int gcd = 0;
		if (n == 2) {
			gcd = arr[1] - arr[0];
		} else {
			for (int i = 0; i < diff.length - 1; i++) {
				if (i == 0) {
					gcd = gcd(diff[i], diff[i + 1]);
				} else {
					gcd = gcd(gcd, diff[i + 1]);
				}
			}
		}
		
		for (int i = 2; i <= gcd; i++) {
			if (gcd % i == 0) {
				writer.write(i + " ");
			}
		}
		
		writer.flush();
	}
	
	public static int gcd(int a, int b) {
		int r = a % b;
		if (r == 0) {
			return b;
		} else {
			return gcd(b, r);
		}
	}
	
}