java算法：1234组成无重复的三位数[通俗易懂]

public class Wanshu {
    public static void main(String[] args) {
        int i = 0;
        int j = 0;
        int k = 0;
        int t = 0;
        for (i = 1; i <= 4; i++)
            for (j = 1; j <= 4; j++)
                for (k = 1; k <= 4; k++)
                    if (i != j && j != k && i != k) {
                        t += 1;
                        System.out.println(i * 100 + j * 10 + k);
                    }
        System.out.println(t);
    }
}