Question

设有一个栈，元素进栈的次序为a，b，c，问经过栈操作后可以得到哪些输出序列？

Answer 1

abc,acb,bac,bca,cba

Answer 2

abc,bac,cba,acb

Answer 3

a,b,c a,c,b b,a,c c,a,b c.b,a

Answer 4

a,b,c; c,b,a ;