321231

要有123這三個數字的組合:123,132,213,231,312,321(相當於對應6個不同字母a,b,c,d,e,f)

兩兩組合:總***有36個

組成6個數字:a_

:123123,

123132,123213,123231,123312,123321

b_:132123,132132,132213,132,231,132312,132321

c

_:213123,213132,213213,213231,213312,213321

d_:231123,231132,231213,231231,231312,231321

e_:312123,312132,312213,312231,312312,312321

f_:321123,321132,321213,321231,321312,321321