Introduction - If you have any usage issues, please Google them yourself
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