import java.util.Scanner;

public class Demo{

    public static void main(String[] args) 
    {
        System.out.print("请输入三个数：");
        Scanner in = new Scanner(System.in);
        int x = in.nextInt();
        int y = in.nextInt();
        int z = in.nextInt();
        //判断相同，输出不同的数
        if(x == y)
            System.out.println(z);
        if(x == z)
            System.out.println(y);
        if(y == z)
            System.out.println(x);
    }
}

------解决方案--------------------

Java code

import java.util.Scanner;
public class Test1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner in = new Scanner(System.in);
        int arr[] = new int[3];
        System.out.println("请输入3个数：");
        for(int i = 0; i < 3; i++)
        {
            arr[i] = in.nextInt();
        }
        for(int i = 1; i < 3; i++)
        {
            if(arr[0] != arr[i])
            {
                System.out.println("不相同的数是："+arr[i]);
            }
        }
        
    }

}