题目:有四个数字:一、二、三、4,能组成多少个互不相同且无重复数字的三位数?各是多少?app
# -*- coding: UTF-8 -*- b=[] for i in range (1,5): for j in range(1,5): for k in range(1,5): if(i != k) and (j != k ) and (i != j): b.append([i,j,k]) print(i, j, k) print(b) print (len(b))