代入以下代码,得:11,9,4,2,1,6 滑稽~2 {$ K1 B* N5 _9 l0 l
4 } n' a0 c0 H#include <iostream>
$ O9 U& H$ U( @' z+ q9 b! d# D4 {#include <string.h>
% b3 v q0 r* T# J1 d9 Xusing namespace std;" d* c0 J9 Q) s/ O- [( c& F: u ]
template <class T>* B8 t; w" t, p$ D
class Node
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public:
( X' \8 v! X3 d1 b% m V/ v0 H T data;6 s7 t; D" w, S% h
Node<T> *next;
% n" a3 x0 a- `' P+ ^ Node()3 J% b: Y& }. `3 w& m: {& |! {
{
' n& D# d; _& O! E7 _5 w this->next = NULL;
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Node(T data,Node<T> *next=NULL) k: j0 T4 H- o' G( E7 |# G
{
8 t& d9 X3 C% S2 ?' B0 P/ R this->data = data;
- R, k! C) k) L) R; r0 j9 T. ? this->next = next;
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};
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template <class T>$ n) D+ x, Y, N8 ]- R3 x
class LinkedStack
: F# H$ r+ K/ h D O{
- S; ]: G t" s; k! Nprivate:
5 f y5 J' `6 ?, a& O6 M* T Node<T> *top;
5 @3 C/ K/ u. Z% a5 ^& \; Qpublic:
" H9 v$ N S6 d2 n: _( U/ w- Z LinkedStack();3 g. b: M$ h* c, T
~LinkedStack();
+ G8 G2 s8 R$ Y" X* v) p6 _2 j6 u3 q bool isEmpty();+ @- `1 D# S1 ^7 k; h
void push(T x);5 X$ ]% `% u7 _5 W. e! s6 L
T pop();
}1 i; l# i/ v" Z F& x' N3 u T get();' W$ F, \2 x: o1 h) t" H
};
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9 [3 ` R! a q2 H# F" btemplate <class T>
3 R, T6 q& G! {LinkedStack<T>::LinkedStack()/ f# n! F/ v; ]0 B' {" I
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top = NULL;
: u6 L3 X% W- B9 V: C' B) X}
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; P9 ~/ \' z& G8 G. j; H) z% ~( Y, etemplate <class T>
- m) Z' Q$ ], X3 GLinkedStack<T>::~LinkedStack()* j" D' F. U2 o6 h8 T1 e
{
- D. S. n) j) Z$ t9 G) X- @$ B Node<T> *p = top;
6 }/ {3 G5 f0 ^: a Node<T> *q;' X0 g# s. K8 s* Q
while(p!=top)0 q2 X* g+ H' B! \6 z( ?9 P
{
: p8 [$ N U) H q = p;: p+ N/ @; l2 Z
p = p->next;1 [4 J7 c* z6 Z' h3 f! z" |
delete p;
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top = NULL;
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9 W8 e: x, {0 i/ W' Stemplate <class T>
, L( j7 b2 H0 p, Y$ C9 ~bool LinkedStack<T>::isEmpty()
) U: k& ]$ {% S& Q! m, r2 E{
' [6 h& N9 B- H' z/ K7 v return top == NULL;
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template <class T>
# m6 X- h. J+ Q- @! d" mvoid LinkedStack<T>::push(T x)
' r, e; s: \, L: U: ]$ g" V{
/ I# Z- f0 _4 n top = new Node<T>(x,top);% P9 s' G9 \# C
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template <class T>0 S3 m/ `; M5 f0 o3 K
T LinkedStack<T>::pop()6 {4 |2 ]' e. _+ F" A1 X3 Z
{/ h7 U5 D' b, _
if(!isEmpty())
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T x = top->data;- ?) T- A- c, e5 [* y6 {
Node<T> *p = top;+ }% L9 y9 @* F8 K2 f. \9 O1 b/ l( `: h
top = top->next;, E6 s z) x2 p5 \5 c; [7 ]
delete p;
, V+ R, q) h% C return x;% }; E1 ^/ J" o, Y4 O/ g( U% d
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throw "空栈,不能执行出栈操作";
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template <class T>7 T5 ~/ t. {1 @( n$ @
T LinkedStack<T>::get()
9 ]5 k2 A% S! a4 r$ k5 K( R" _{
! a9 t+ i- ], {" W, |4 H% ] if(!isEmpty())
; S; Z. R% E4 b9 W( O3 G# D {
( T6 E, d; _! s6 f2 q. F return top->data;* s: i! f7 V( ?$ {3 ?& }) w1 A
}
7 h7 p$ M! f( u5 J throw "空栈,不能获得栈顶元素";
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/ t, T6 k% b- J% D4 ^1 Rchar * toPostfix(char *expstr)6 ]/ O X* |; }* S9 B$ Q1 N
{$ d1 Q) q X" o. f
LinkedStack<char> stack;
! e# w- q5 ? A+ z& s6 o1 s# O/ v5 r char *postfix = new char[strlen(expstr)*2];
0 a) s; a- h3 I5 A+ E int i=0;& v4 }1 k: T6 [6 p
int j=0;
2 S* Z1 d1 X4 w3 g4 a' { char out ;, l Z4 f L T" E4 F1 o: U/ n
while(expstr[i]!='\0')% D1 q) O9 z" t" z" O9 V
{
6 { }* o2 c" s V/ V6 m/ c/ D' h switch(expstr[i])
! }2 [& N0 ]9 f' }- s. q {
/ z6 r8 m X( ` case'+':
1 {! U/ u0 _* V! R) \ case'-':
7 m+ L2 B1 b2 z: j+ l' j- j8 x while(!stack.isEmpty()&&stack.get()!='(')% U) P+ N! s# g- ?% k& b. P8 G
{
$ Z2 O. s- p. X+ G! I# n5 k: } postfix[j++] = stack.pop();
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stack.push(expstr[i++]);" `; ?! r% }2 u% r5 q8 y1 [
break; H( z3 e [- T0 C1 ^' {
case'*':7 ]. O& A! h; b2 p0 U
case'/':4 Z, U- C9 u1 [- C
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))
3 n5 ^4 y5 N7 @ {
2 [# _; p4 n/ W2 `0 I postfix[j++] = stack.pop();
- M6 P: i& | H$ b7 a, T9 ]3 | A- j }
$ X, x! D9 K% W. F2 {5 @ stack.push(expstr[i++]);/ z" C! l% L' u
break;. {1 r, V2 U- a5 |
case'(':stack.push(expstr[i++]);
4 ?4 l, E' a1 p8 z, X break;. C2 J7 N( q! Y
case')':out = stack.pop();
0 r/ ^7 b6 \" c" i' @! i f$ } while(!stack.isEmpty()&&out!='(')
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postfix[j++] = out;
& E6 ], W/ v* H( {+ } j out = stack.pop();4 U4 _( Q9 E( I( A8 n
}
) f$ \0 }0 N0 L. E6 ` i++;
$ D& m. l/ A9 M% t; i+ E! [ break;
' s8 ]" z- b) }2 p8 ?. Y5 T default:
/ Q& G; h' ^; L while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')
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postfix[j++] = expstr[i++];
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' H& j; @" z( |/ l% d# W postfix[j++]=' '; v0 w6 e2 b# j, f
break;
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9 }( D- |( Z9 \& E0 }1 {, ] while(!stack.isEmpty())
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postfix[j++]=stack.pop();
9 y: B1 y3 }& o }
4 c, i2 _( `* q postfix[j]='\0';
4 H: p( Q& N4 O return postfix;; L8 F) j6 Y5 y, A1 z/ x
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o9 Z1 ?$ i+ v/ s) Z# f
int value(char *postfix)
: @ r3 Z: a! \! X' E0 W5 n# q{
% O. V9 C( @9 |3 f+ z5 u0 p LinkedStack<int> stack;3 Z6 \# o; r a+ x$ |7 c
int i=0;
6 ]2 L/ j& G# S5 g+ \1 {. ?, ?! g int result = 0;/ N2 |" L, R; u- l$ ^+ [
while(postfix[i]!='\0')1 t3 H w J2 X, G. w
{4 J8 o2 V# v' R5 Q
if(postfix[i]>='0'&&postfix[i]<='9')
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) U M. ?7 w* Q0 K/ a/ [ result = 0;* u" M# `' R% l* l8 y- S
while(postfix[i]!=' ')( [) Z7 r/ {( j7 V9 V
{$ T% q6 R9 I) @+ `6 |4 r
result = result*10+postfix[i++]-'0';9 E! K3 _' C) ~* h
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i++;" ?: \% A. i% t
stack.push(result);
_ _7 ^. g+ Q8 c, w9 Z }
3 g; J' O" j, ^2 ]0 V+ l else
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if(postfix[i]!=' ')
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int y = stack.pop();
( F' c1 {2 N2 Y5 g z8 b int x = stack.pop();( w6 R+ ]9 |' M$ i- l8 A
switch(postfix[i])% g7 F3 K; x' d
{
& c, ^5 V: }, ?: j1 W case'+':result = x + y;3 e8 |2 Y" H7 Z: x
break;
2 }- S2 Q" T: ~9 L( A0 Q" u+ o case'-':result = x - y; h; a: Y8 i$ ?+ p/ b( d
break;7 Y/ h. ~, n/ T. [- u
case'*':result = x *y;/ L% p d8 X. U4 h
break;
3 }- s, P4 ?2 J9 x6 B1 ?8 a5 F case'/':result = x / y;
2 Y1 b) l( [) G9 j7 x break;
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stack.push(result);/ ~( R8 x3 q [; r! p/ Q
}9 x! j# P" J/ [* T
i++;& ?5 D6 U5 ~5 O3 A; ]! u/ p B6 ? \
}
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return stack.pop();2 O+ Z- Y f$ o$ g/ r
}$ S' ?, O7 J, s$ i6 I
& Y* V8 L- j! Lint main(), R7 O0 W# z9 h9 _' ]
{
# V: m( a, J. ~ //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
& k, H; a6 F5 |* G" P cout << "请输入表达式:";0 G7 q4 p& I/ U' A2 j, y
//char *a ; ?, j2 P5 B" I( G/ H' {
//cin >> *a;
) e% T+ d: u' T- s char expstr[20]={0};# w" T$ @; P0 ]/ k
while(1)2 M1 [( F( `* Z& P
{
, I" S7 A2 K) `( ?1 Q- o4 B7 X cin>>expstr;
; u# Y+ ^( c% I( q) N2 J char *postfix = toPostfix(expstr);) K4 D( B d. D
cout << "expstr= "<<expstr << endl;7 f; Z2 H' p9 j3 \! r( M
cout << "postfix= "<<postfix<<endl;
( y0 u3 O" s1 M6 s% w! B( E cout << "value= "<<value(postfix) << endl;
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return 0;% z ^. j3 H2 b+ H8 @, j
} |