9 ?" Y6 u! } G/ t& r7 k代入以下代码,得:11,9,4,2,1,6 滑稽~. I8 `9 j' Y1 }* ~- ?7 C6 s3 |6 w8 T8 Q
; g, a- i; r5 I6 e/ w" f* ]3 C#include <iostream>
6 o* ~$ X& a' R% w+ \- p! ~#include <string.h>
- _, R- D4 d: Z6 ]9 Busing namespace std;! G/ F7 E/ I& a. n8 a
template <class T>
2 R9 c. F0 x* P- N% Cclass Node% ^/ Y B" }' q) S+ x ?
{" ~# g" w/ `, [- H/ r
public:. C7 J2 t5 D0 A! [7 q T: `
T data;
& T* W* E2 Z: _( G& s: _ Node<T> *next;
. [: `4 P0 p, d+ T1 l: W! |. W Node()3 |: J: h- K% }5 r+ X) [
{$ M2 E3 E2 T4 U$ J- |4 `7 j# W
this->next = NULL;% W. k1 S* ]7 e; ~ \7 c6 e9 |
}
0 |# Y% r( U9 U, h4 ^ Node(T data,Node<T> *next=NULL)) l" L- V; t+ z2 Z; y6 W" w+ n$ _
{
' G+ D9 m+ M) A# K+ }: n this->data = data;' B6 K6 v) G- p' Y
this->next = next;
1 ~' E! i) a: R( |) S4 d7 ? }
, v J, Y9 c! e) J4 T( z};
! b! ], `# ?1 j& p# J/ [
s' r) l& j6 y) a& stemplate <class T>. V, O2 s! ? p+ |) {
class LinkedStack& p8 k5 Y& U0 S! P" t
{" h0 m. o1 w5 s; I
private:' h7 Z* U9 a4 ?" v0 U- v
Node<T> *top;
7 j$ U9 ^$ K: U+ h+ E: l6 P, gpublic:& N! ?* v. h5 o; t! {+ l7 _
LinkedStack();1 q3 l4 q) y% r; S; W
~LinkedStack();2 Q4 l2 r( O5 C& D8 Z4 z
bool isEmpty();
5 p+ n: ?7 X3 e4 u4 R2 X* t: E( S" V void push(T x);) L5 \( M" m- L$ M Q- X
T pop();
+ f9 J$ w' ~, j: ^/ D T get();
; {' R: S, ], @; i' l$ E};6 \6 c9 ~; M. q% Y" H( r
" v5 o! \6 E8 P$ ]$ \" k0 K/ Ztemplate <class T>+ P* {( I1 U+ l4 \% @
LinkedStack<T>::LinkedStack()0 d0 f; _- G! t) W7 O3 e
{
3 ?% u% W" Y/ J. \5 ]# E0 k7 n top = NULL;. {5 G; H3 z: V% W( S5 w! a$ P
}
0 {5 I1 g3 I6 z8 K! i2 E5 f4 K2 A. G
template <class T>7 r) Z# c& p! a+ O7 A
LinkedStack<T>::~LinkedStack() M, [/ F' U# O5 j$ J. K0 K
{
$ A9 x5 n# v) ], u Node<T> *p = top;
' K: A4 }2 L9 z: `) d0 ^& q Node<T> *q;
4 R" r9 O7 P& {! c4 t& u) D0 p! W while(p!=top)
! i& n) ]* B" K h/ I) p7 M x o {7 r+ n8 V6 g5 w, G; g/ _1 {5 G, L
q = p;
5 w9 \8 n$ ?4 q$ @ p = p->next;1 U1 E) e& A- i2 g
delete p;' W% Y; a. v1 @4 f; _3 O
}
v9 k- P6 @- b+ V" w top = NULL;
" ]% f$ y! \ ?7 a9 d" L}1 W/ |! j" v r4 J5 f! |) U& x/ ]
. W( n) P, e; X& t3 a: T; ~* d, ztemplate <class T>+ s& E8 O0 m, f: w- o
bool LinkedStack<T>::isEmpty()* H- w! X- ]& [' h) z, f6 p: }
{( q4 l1 T# @# A; G
return top == NULL;
3 B, w, f2 i. o. o}7 R- h1 P3 f" [! a. `/ W% E
6 P- y& M" U+ U+ `template <class T>( r( O% ^0 r+ @! \; ?. N
void LinkedStack<T>::push(T x)
1 p. @1 L7 u/ |! ~" D8 | W! g# D{
( O& \# t8 W) q; o$ Z: C top = new Node<T>(x,top);
U3 o0 e; l8 R' V5 a% U}& Y0 ~1 e9 D: w% Z3 z0 R$ v% C
$ n+ P4 Q: C% x! h9 s6 r4 L6 n
template <class T>
9 y. C0 g9 a, N0 {T LinkedStack<T>::pop()0 ~% r' z2 R, S" l3 ~
{, a7 H2 h0 V+ T/ l' k, p2 S$ b
if(!isEmpty())
' W: V/ K% [ G. I$ S* o {; F' [9 w l# X9 {
T x = top->data;1 s1 X& D# v [
Node<T> *p = top;
4 Z# t/ I8 C0 B( e: O top = top->next;
0 ]$ @ s6 ]% O& | delete p;+ T3 s, r7 s6 Z" D; ?
return x;
' R6 a' z5 Z2 l, y/ w }
0 P3 U: K% J7 q4 c* |0 C throw "空栈,不能执行出栈操作";4 T, d7 v$ _, j& U' k
}
5 B" e2 y2 b6 R0 X/ ?$ l5 |
) V0 c; c4 X, O! D4 F3 @. {template <class T>. p- B" j9 ^0 _" u% y
T LinkedStack<T>::get()
6 T8 F) q" v ], X/ O9 K{
: {1 X, X* ?) C" e) \9 _8 D if(!isEmpty())
, u4 p7 t6 s" r' a9 s& v7 Y {
' M% ]/ H$ I1 E return top->data;
4 _9 l% { k$ A* h$ j+ Q) ? }% `0 O" [: b1 |" V
throw "空栈,不能获得栈顶元素";
& C# {7 |6 o* J+ Y& S}" o0 r1 q0 o6 D0 U0 R% D
* _ I9 t* K4 F2 c
char * toPostfix(char *expstr)9 A, w) M- |6 D
{
4 h) B l. Y! `" O& `4 [& R- g LinkedStack<char> stack;
! i; B# q" T9 f% S6 P char *postfix = new char[strlen(expstr)*2];6 \4 ]( c3 H# h
int i=0;: Y! d! W n+ d! T% {) l
int j=0;) d1 d$ n5 y N9 Y6 `
char out ;
, ?+ [* [. W* {/ V* n: \ while(expstr!='\0')
/ V# F( n, y9 w+ i8 z% d: ~ {
# i5 H7 Y7 i4 m- r: ~! c2 U- q4 k switch(expstr)' q3 E ?) e0 Z9 K( t2 y
{# }, a- _; G4 f; x- P) @4 I
case'+':( y- c5 T- U9 C9 O4 { N1 e0 N
case'-':
* n0 \. h g. l! A5 B) R while(!stack.isEmpty()&&stack.get()!='(')
2 W9 N0 e" ]5 y- d* U* [7 _ {. ?7 C0 f" p1 D- ^* n* t5 _
postfix[j++] = stack.pop();
& M' {" I# L( r b }
: h% p# Z! B& v2 p' M7 N7 f$ U stack.push(expstr[i++]);
3 g; Y% P4 ^' N4 j break;5 N/ c/ i* X$ r8 r9 x. n
case'*':
$ @9 p, J8 g' O case'/':* d0 V# D+ g0 o
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))9 d8 H4 C6 m! e0 v4 R) J5 u5 [" J
{
7 B+ |, \3 ^5 M3 ? postfix[j++] = stack.pop();" w, s8 T, v* d9 v' H9 j; P
}
- Q" B6 U& `5 e' @* A# W* ]) M stack.push(expstr[i++]);) I& Z. t @( V1 Y) L2 r
break;7 y$ s% J8 c, H2 l/ |( P: Y* q2 B
case'(':stack.push(expstr[i++]);
) R! s1 t+ K6 ]6 I: h break;
/ J) q* U0 a2 a- t* y, N( J case')':out = stack.pop();
7 b( r4 [2 \7 t+ b+ Y" Q2 k( B: J while(!stack.isEmpty()&&out!='(')1 A. W6 b6 w) C1 Y M$ Z
{9 r, W+ I# k4 t
postfix[j++] = out;
2 e+ e1 ]/ y2 h' Q+ |0 l/ w out = stack.pop();. r4 D4 z. I( z4 ~5 W
}9 e( z! ~7 Z. R3 l
i++;
0 s1 L# ~; V5 K5 [! ^ break;
6 q1 ]$ I3 V [- S default:
K3 B# ^$ y' @) b+ X# f while(expstr>='0'&&expstr<='9'&&expstr!='\0')" J( ]- y1 p0 X
{* H! [5 A7 h4 ?- j- T" A) m9 s
postfix[j++] = expstr[i++];$ n! D* _0 B" F' F8 q1 E4 ]
}- C3 I3 n' ~7 w+ A3 V. b
postfix[j++]=' ';
& k, V# e' m$ n* r4 [% b break;
4 A- S5 q% p8 B% Z1 S' l& y9 L }" u) q8 Z! t$ ^0 t& o
}& L: h8 Y: T4 ]& W$ r5 y1 q
while(!stack.isEmpty())6 _3 m" W7 P) |' i& y3 }0 G
{
" R6 G: B) ^$ Q6 l+ S+ ^1 ~2 a* n1 g$ \ postfix[j++]=stack.pop();2 D6 i1 w p; I2 `
}
- b. x% Z8 B# ? postfix[j]='\0';3 m* ~0 p! B* u* r: ]8 C
return postfix;
% z3 \6 n7 ]2 k6 s}2 i/ X3 y% B8 w8 u8 N
' \% S6 y* M m1 O2 w/ L# Wint value(char *postfix)4 ]# {7 V/ M+ n
{8 `$ D% Y; h$ F+ U
LinkedStack<int> stack;* e7 T6 ]9 O; \( Y0 u
int i=0;
1 o4 v4 y+ E% n8 j: h1 L int result = 0;
& k0 A S2 k/ A while(postfix!='\0')
; e- R2 r: n M9 j- M- b& j+ k {8 r3 {1 v3 j) e( r5 A) L* [( n
if(postfix>='0'&&postfix<='9')* ?& Q( D: ?- B- _/ H
{
2 r" L G# f7 d. s) x result = 0;
$ B2 b; D# w7 x+ r- s! p while(postfix!=' ')
8 P: C2 U0 Z/ t. l# W/ }( @ {
7 U9 O$ ~3 x- @) G$ ~ result = result*10+postfix[i++]-'0';
+ x- J9 v! u+ _0 \3 m. P }
, w& g0 ^9 g# I6 T. A i++;
% H' ]9 |7 A* P( m& u, D1 H stack.push(result);
$ S3 [0 h. y$ n }$ v% L9 [9 c, [! N9 w
else
! Q6 {& v( n& B/ m( I4 F {
( U# h3 c& ^ B# e& d7 g5 \ if(postfix!=' ')# P$ ` L1 o7 T* y) ]& E0 C1 d
{- M- ?; ^% ^) P
int y = stack.pop();$ K5 z9 n5 N5 D7 \
int x = stack.pop();
; A' }( v9 H H. I: K: S switch(postfix)
* B' ]5 E% [( x+ ?; Y, j {
( x2 k8 |# Q: K2 F case'+':result = x + y;- |4 w. Y8 y1 X' ^6 y
break;
0 A" k3 r9 ^1 T k case'-':result = x - y;
; W0 P2 p6 v! K. o0 v+ j4 J break;
7 n J M, g& m5 u case'*':result = x *y;
. b4 B2 w3 T, x7 c break;
( T4 j3 m% `; W3 X* h7 _ case'/':result = x / y;& L3 C' p/ Y2 a0 W/ g/ ^
break;
2 H; e9 I2 ~' d! {3 t }0 n0 g/ K& h5 a2 W2 K% {
stack.push(result);
6 U& O+ r5 G& y5 q- r) p }% }$ k$ l7 W2 A& N7 S
i++;
. U! \$ O2 r1 Y. M6 T8 q. p$ v% M }& S6 Z: R, e) E" l4 e& @+ [+ M
}
4 x' `# K4 x/ _* y( S8 G return stack.pop();
' G; w) r5 S( s}
* _2 r8 D4 u7 a9 @
: T' u9 }) j# g7 iint main()
) T, \+ b& T$ {. P$ G2 i{
) t7 o" e: T; ? //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";) ?8 O$ }9 e3 c; ~
cout << "请输入表达式:";. r' }/ K" T" S) ^* V, x# v
//char *a ;% [- k# Y6 n+ a5 L y0 o1 K
//cin >> *a;
' x9 i% r( f# E, Q- m0 |! A5 g F+ b char expstr[20]={0};
# {* ^: x% P7 F while(1)
; S- [1 K* o9 {9 M: \ {
7 U7 C9 C- p, V1 y+ ^3 ? cin>>expstr;+ D1 Q9 f9 z6 q% i
char *postfix = toPostfix(expstr);. j: o( @1 q, B5 w
cout << "expstr= "<<expstr << endl;9 ~ v& r' d/ E$ E* ]' f
cout << "postfix= "<<postfix<<endl;
) M [5 B n% T6 m cout << "value= "<<value(postfix) << endl;
, Y% R1 u9 G: P4 b1 q }" @ ]5 Z" L |+ m. c
return 0;. F5 t4 k3 H( D7 \
} |