[Silver 2] 17087번 숨바꼭질 6

import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] arr = br.readLine().split(" ");
        int n = Integer.parseInt(arr[0]);
        int s = Integer.parseInt(arr[1]);
        String[] a = br.readLine().split(" ");
        int[] distance = new int[n];
        
        for(int i=0; i<n; i++) {
            distance[i] = Math.abs(s-Integer.parseInt(a[i]));
        }
        
        if(n == 1) { System.out.println(distance[0]); return; }
        
        int max = gcd(distance[0], distance[1]);
        if(n <= 2) { System.out.println(max); return; }
        
        for(int i=2; i<n; i++) {
            int temp = max;
            max = gcd(temp, distance[i]);
        }
        
        System.out.println(max);
    }
    
    public static int gcd(int n1, int n2) {
        if(n2==0) { return n1; }
        
        return gcd(n2, n1%n2);
    }
}