5个福娃排成一排照相,欢欢排中间,有几种排法.
问题描述:
5个福娃排成一排照相,欢欢排中间,有几种排法.
答
我用1、2、3、4、5表示吧.欢欢是31.123452.143253.143524.123545.153246.153427.213458.213549.2431510.2435111.2531412.2534113.4132514.4135215.4235116.4231517.4531218.4532119.5132420.5134221.5231422.5234123...