Introduction to Stacks 习题
(a) n=3时,有五种
123, 132, 213, 312, 321
(b)n=4时,有14种
1234, 1243, 1324, 1423, 1432
2134, 2143
3124, 3214
4123, 4132, 4213, 4312, 4321
(a) n=3时,有五种
123, 132, 213, 312, 321
(b)n=4时,有14种
1234, 1243, 1324, 1423, 1432
2134, 2143
3124, 3214
4123, 4132, 4213, 4312, 4321