代入以下代码,得:11,9,4,2,1,6 滑稽~0 ~0 G' L* q- ^( y3 b( o! ?
" d* Q# J4 C2 M! C ~3 C; ^1 D#include <iostream>
; x0 s7 N# D% A* i#include <string.h>! q2 n' v6 U r: ]' J
using namespace std;3 ?) p9 Q v) o, z6 y5 u, K9 v, M
template <class T>7 e: m) x+ A" C
class Node4 a! W0 F$ K8 C
{
, y( F: M/ w$ e# N) \public: F) i3 X' s. g
T data;
/ `5 {2 X" q5 F! N3 N" J: ^ Node<T> *next;* Z" }# W# t T; e& k% _
Node()) X3 x2 Q/ W' `/ J% T
{
" I! t6 N& s8 C, r- s, d this->next = NULL;
$ L3 I6 F1 G+ O h( M }
: f- V9 d) G+ \) Z) ?+ D X. w" h$ S. ? Node(T data,Node<T> *next=NULL)) G$ \7 \8 }# D5 ?
{
0 ]* P! \# @ b/ e) i' k this->data = data;' C$ ]( ^ V+ h& F. O
this->next = next;
6 J2 W) n5 B' ~6 e }
# z" ?( z6 T* {# C6 G: p( B};
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template <class T>
8 r3 x+ w- R7 n9 ~+ Lclass LinkedStack
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private:% j- ?1 y$ X7 }: s
Node<T> *top;: y. U# l5 W1 n( X. h
public:
' Y: x% B' c& | LinkedStack();
, \5 l+ Z+ J2 u9 {! i! T ~LinkedStack();
0 V" x6 H4 R* `2 z bool isEmpty();
. F# \' ]3 j5 h w void push(T x);
7 `5 S* V! @* x* B T pop();
( M! B/ o7 F# X! q) c- `7 q% q T get();, s1 f5 h! n: ]! w# J
};
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template <class T>
5 I* K, i) ?! r" DLinkedStack<T>::LinkedStack()# A: a' A9 {1 ^& n4 ?
{
% c( m, r6 q! j0 H% p) E0 A9 _/ A# a3 ? top = NULL;
, k0 G3 P4 U' E1 L; }5 v( M}
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+ `$ ~9 Z0 s/ v* ]1 Utemplate <class T>
2 Q. `1 L" d# A7 XLinkedStack<T>::~LinkedStack()
& u( I! {" v% r. g{
( l7 [7 q& ?$ Q" M0 @ Node<T> *p = top;
G+ z/ [5 ]/ a0 q1 z Node<T> *q;
! P9 V, X% i# ]& R2 q | while(p!=top)( U( a8 _6 A! X
{8 e; c# b9 a9 A @/ r! ~! z/ |( N+ A
q = p;/ t* a1 @& q" N8 O1 v- G3 `
p = p->next;
) g; h' q2 h! X delete p;
3 [% q }% J$ l0 R" z# l; X }: r3 L1 [1 v9 ]" _9 K
top = NULL;; r- g& b6 l4 I) i$ _7 L( \
}
: b; {. \$ z. H3 A' _* C
2 Q8 B4 T, N( ~: o( ^ itemplate <class T>7 G2 R0 N' p6 Q8 u$ T
bool LinkedStack<T>::isEmpty()9 X6 ^7 T- n3 G0 {
{
7 w/ E0 }1 W& x$ b. ?; v& k return top == NULL;
) r- C# J5 R# z" K$ }}
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template <class T>7 T$ {( a0 Z( w9 n: l8 D- p
void LinkedStack<T>::push(T x)
, D) W$ e( O# `4 e9 v4 C; ^, z C{
F1 J) a- @$ t+ G top = new Node<T>(x,top);2 i$ l' ^0 {! k0 x
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template <class T>- \' e1 y: Y; A; ^6 ^' X
T LinkedStack<T>::pop()
" @( x7 V' a, e; p- _3 r8 _{* ]5 {7 r9 K% j7 r* n- ^
if(!isEmpty())
% D; Q: J h* m9 F7 _# T {
: |5 l+ J; _! W7 C' H8 H5 w: f; G T x = top->data;
- F; Y( e2 {3 { Node<T> *p = top;
5 r% F9 \: @* [* V" M9 R- D) Z: v top = top->next;6 d( T% Z* j9 U- e
delete p;% l# [7 [% X P+ E$ S
return x;. E2 ^' d4 Z X+ E% S7 Q
}9 J' J2 A. c! C/ i
throw "空栈,不能执行出栈操作";
' q8 ~+ n1 }# ^/ \}
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template <class T>
* H- o# z/ b+ N- r$ uT LinkedStack<T>::get()
1 f6 R# i5 Y0 C- v4 m8 K7 `7 P3 V{
. c0 S: [! d+ q+ \ if(!isEmpty())% E3 o; X0 A& A2 O1 V
{# ]) N5 g% @4 m( w8 R+ ?7 U
return top->data;% |# p4 V/ `# T0 [" w
}" e+ t9 `8 Q$ K* w! E, X5 ~( d
throw "空栈,不能获得栈顶元素";0 T6 y7 K0 K5 K+ j1 B+ x
}: ?0 Z$ s D+ B, {# ]
7 V9 d, L2 J$ H) T6 a5 \char * toPostfix(char *expstr)
5 z) |7 m3 ]9 y3 H) c/ o0 q& j{' h: _# }. x; r) W* y% J
LinkedStack<char> stack;
; N& x0 u. H$ n5 s8 }5 G char *postfix = new char[strlen(expstr)*2];
' ^7 T2 G0 W z int i=0;
) {6 Q/ I5 f: @* P& T int j=0;
# x' c' Z% L2 L7 I char out ;
" {7 X% M! _2 q while(expstr[i]!='\0')
" j* F7 [9 @5 @8 y" D+ J% ~. l {
8 m& V# N3 T# s$ f! ? switch(expstr[i])
7 V2 \2 [; b0 e, Q% ~ {
% x6 F# L; F; m% O& T5 |. l case'+':
# d3 S; X% E0 y X6 a, J& g7 l7 c case'-':8 u+ j! D N5 [( ?) m6 l
while(!stack.isEmpty()&&stack.get()!='(')0 r+ A4 T8 M' B. _" J- h
{
- Z* P; W! g" i2 b, W3 Z! N postfix[j++] = stack.pop(); H U8 S5 `: a/ c& U9 i* b+ g5 e
}
0 }& A# k5 T: L9 g& `& y" P l stack.push(expstr[i++]);8 I) h3 d5 a* t5 ^/ d
break;
, T7 A+ p5 m& r case'*':
/ ]6 A( V3 L% d" v& _7 X1 ]3 d# Z case'/':
/ ~5 G' s9 q( k# @$ \- v while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))) y- z5 c9 Q2 e: p* F: ~5 p
{
% p5 T/ v/ ` k$ Z4 u# Z- G postfix[j++] = stack.pop();1 I4 i- ~! o( r. G Z4 {4 E
}2 `8 d' W; h- [+ _3 t8 }
stack.push(expstr[i++]);
, h# L1 I3 k* _ break;
# A* [8 b( w0 E1 Y4 ^6 j7 g case'(':stack.push(expstr[i++]);. e; R& U+ ]! U! z/ _- x2 ]
break;; u" \+ ~5 T$ E
case')':out = stack.pop();
1 Z+ ~0 ^7 } [3 { Y while(!stack.isEmpty()&&out!='(')
! E6 X0 r, o, @: f, ~ {
# E2 m5 B& g. T/ C3 c- T postfix[j++] = out;
. C2 m) [" S9 |& Q% u( g' \ out = stack.pop();
, ?% j- f. B' h' F }: J* J: k9 x" p- f/ T' C
i++;
, E- R+ o9 Z( Q4 X0 }* j: [ break;
4 z1 g% J8 g6 ]8 U default:
& x0 U- M% O4 B* I( f while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0'); @* b( b# q6 K) y* Q
{
$ }; k; G2 o, x" z0 |+ d: Z6 J postfix[j++] = expstr[i++];
; S$ O( e, c$ p0 k! r }) @2 h3 f2 H3 c3 y
postfix[j++]=' ';
- D& Z4 y! b! k1 ~9 R9 ?. P& F break;# \9 [9 y Q1 l! y( K5 P. Z! y
}, A5 N, c; L w, B( W
}
+ m* R% C9 H: Y: I/ k* x) p% C. ^ while(!stack.isEmpty())
% |; m0 ]; v" x0 u, _) M {- y/ U5 V o+ q) o# {
postfix[j++]=stack.pop();
# b/ B+ |1 H, O/ o }
. o+ B0 B) {. \7 L0 j, k2 w postfix[j]='\0';8 m) {% X+ \' L1 @ }7 j2 w: W9 F
return postfix;4 r. g6 U: D1 Z/ V- ?+ v
}% z. b1 P& k9 F, k8 Q) Q
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int value(char *postfix)
/ J t2 g& b( @; S5 M$ u( T{
6 x( o( z' ]* Z1 Z. g LinkedStack<int> stack;# V9 I' s7 K1 ~) v+ r9 Q, n) E
int i=0;
2 `3 H5 e! Y5 B1 D int result = 0;3 }# R4 p: [( h( b; b3 X. M8 K
while(postfix[i]!='\0')
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if(postfix[i]>='0'&&postfix[i]<='9')0 i: |/ }6 _! l( T8 t& \2 ?
{6 L7 f; }, M6 _! a" P% T, h/ K; \
result = 0;
; r' E3 s5 L6 A while(postfix[i]!=' ')2 U& I; U# K1 T7 P
{
- Q- t3 ?6 H2 K, ^2 V result = result*10+postfix[i++]-'0';
6 b4 [. {% Q4 ~ }2 X, J$ L" w# }. c& |
i++;. U8 {, p! l2 |. E0 g* E
stack.push(result);$ n4 ~* k9 K0 i) B; {# g
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else
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if(postfix[i]!=' ')
* W8 i7 h% j/ c {
; `' g" `: H! b- f) R6 q int y = stack.pop();
7 J! c+ A0 M2 P int x = stack.pop();8 k" W0 b: R3 @
switch(postfix[i])0 F) w: c* v7 M- m$ w5 X. B {! L
{
) b: V8 R5 } E. T6 l6 w case'+':result = x + y;+ l# o" v4 p( }5 _4 E. R* ]9 a
break;
6 E' X/ F; [( \ ~- a i; F case'-':result = x - y;
& h ~$ ` G! y. q break;% I7 K# E: v! a d; s
case'*':result = x *y;
3 D$ c$ }5 T$ m1 v5 G) t break;! `; {2 ?0 V( v/ Y8 k
case'/':result = x / y;' w# a, n" p- x& g
break;! S+ z0 l& Q4 R8 `; L0 S' k( x! w
}
8 ]# y% R. K; |% D x0 p' I3 B/ ^ stack.push(result);, g/ |, Y: p; L8 `) h
}
% ?% b4 W$ I2 I+ i i++;
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}. G% j( F) u- n2 r
return stack.pop();
$ {5 G) _& t T: u: y+ A& V}
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" y4 e7 D6 _" z) @int main()6 m/ @8 I3 S8 F; V* n4 V, b$ y4 k
{
9 N- s. [+ v8 J: G6 K //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
+ J7 O! I2 `* l! i# i cout << "请输入表达式:";
9 ?% V; T$ _8 n0 J, D# P9 d //char *a ;
& D, T' V( X. E, [6 R4 i, Q //cin >> *a;
z+ |! ~+ h, ^5 \0 F char expstr[20]={0};$ W* g: N. v5 @) @4 T4 y
while(1)3 w, a1 t) X1 t- o! e6 z
{. M* \" u% X) X5 ?+ f& ?% w
cin>>expstr;0 ^$ @$ n. n( ?! }
char *postfix = toPostfix(expstr);+ t7 T& x ]# K
cout << "expstr= "<<expstr << endl;5 J( G3 b) F; t) @# }+ @ j
cout << "postfix= "<<postfix<<endl;% Y* @7 i: `0 f- O9 c" t
cout << "value= "<<value(postfix) << endl;
/ d9 P; h z6 R6 I- v }
+ q( {/ m; F7 g return 0;
) M/ r0 s/ Y0 T/ M2 {" u* b0 n" t} |