题目：有1、2、3、4个数字，能组成多少个互不相同且无重复数字的三位数？都是多少？

1.程序分析：可填在百位、十位、个位的数字都是1、2、3、4。组成所有的排列后再去

掉不满足条件的排列-Topic: 1, 2, 3, 4 Numbers, how many can form a different from each other and have no the repeat number three digits? How much be?



1. The program analysis: can fill in one hundred, ten, bit number is 1, 2, 3, 4. The arrangement of all to go after



It can t satisfy the conditions of the alignment