C program làm việc với Stack

a+3^3^b*√(x+7)  / 9 kết quả là  a 3 3 b ^ ^ x 7 + √ * 9 / +

gặp         stack                      kết quả
a                                              a
+             +                             a
3              +                             a3
^             +,^                         a3
3              +,^                         a33
^             +,^,^                     a33
b             +,^,^                     a33b
*             +,*                         a33b^^
√             +,*,√                     a33b^^
(              +,*,√,(                  a33b^^
x              +,*,√,(                  a33b^^x
+             +,*,√,(,+              a33b^^x
7              +,*,√,(,+              a33b^^x7
)              +,*,√                     a33b^^x7+
/              +,/                          a33b^^x7+√*
9              +,/                          a33b^^x7+√*9
a33b^^x7+√*9/+