用1-8这些数字组成四位数的数字

问题描述

精选答案

按照排列组合算出有1680种组合，例如1234,1235,1236,1237,1238

1324,1325,1326,1327,1328

1423,1425,1426,1427,1428

1523,1524,1526,1527,1528

1623,1624,1625,1627,1628

1723,1724,1725,1726,1728

1823,1824,1825,1826,1827

2134,2135,2136,2137,2138等