代入以下代码,得:11,9,4,2,1,6 滑稽~ b; T' ^# u& I8 i+ ], `* O
: H3 v0 O) @" P& B6 }3 j9 H#include <iostream>
* z0 O F7 O* h1 w, i. e( w% Y$ {#include <string.h>
+ D: J, @ L# Qusing namespace std;# _$ s' P0 B8 {' ^
template <class T>
. u3 i) x' B; ]0 wclass Node- T7 U8 R0 O3 e, b- D% W# c; }
{
2 |+ O% f; R# x/ H' qpublic:* S9 b# Z" S4 ^ e: \
T data;
2 O/ F+ Y! [9 u Node<T> *next;0 e) k. W& X6 U* F
Node()1 B. Y/ F) g6 X o! Y3 R; Z
{
5 q* f3 c( O( s2 {' w this->next = NULL;
2 X; ^: H# c$ X3 a! b. x$ M+ R }. \% x1 M V3 e. D
Node(T data,Node<T> *next=NULL)8 g4 k. r, a* A7 S5 b$ H9 K
{/ g8 ? k# z; V9 z
this->data = data;; Z# s3 C" s- ]# D5 ?9 F7 L
this->next = next;$ [2 }; ^& K. n, \" U& t. ]3 G
}
) r. t2 K: {; M. h3 x t};
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0 j; S& @3 b' S4 D* y* Gtemplate <class T>- u6 a! x- n2 I, F
class LinkedStack, Y+ v3 h/ b) P( \
{
/ ?% S" p \+ T& r! e& R, Y1 fprivate:
9 M$ f$ X2 T, R$ A8 i2 \ Node<T> *top;
$ h" r, M* D% Xpublic:
- A; I' G" V V. X% q( n3 h0 _# k LinkedStack();, c) N) G- X6 b. \8 t4 p
~LinkedStack();
# O4 U7 E" H1 [) A9 r$ h bool isEmpty();% n2 n! w% L6 [9 {+ E6 c% l$ K
void push(T x);2 h; t# C+ P+ ^$ Q- X
T pop();5 z9 a+ i; F, j' p
T get();
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2 ], P2 b' O0 Q" _, \% K5 n4 Mtemplate <class T>
0 I# T5 t: p* ~2 XLinkedStack<T>::LinkedStack()
# h# d, t- T' D! Y{
: Y: R- E+ i3 n- E% H& H top = NULL;# k8 d$ x! @2 {4 L4 X+ b# X
} y1 M: T% R. u g
$ w# }8 U9 T: Q% J, Dtemplate <class T>& U2 S4 F' `9 M) T, F3 y
LinkedStack<T>::~LinkedStack()! q. t9 G* m& j" `: b; L w6 U
{" M. W: N5 y% m# ~1 a
Node<T> *p = top;
+ Z1 M% t7 }0 k3 ^+ l Node<T> *q;
r3 l2 @7 X3 S3 A, u while(p!=top)
+ k1 e7 Q3 T5 s1 J8 @ {+ N4 ~: p! j( B3 S$ z
q = p;
! j' E) K3 S7 j. S4 V( t5 E# O0 ?% G p = p->next;0 s9 X* v7 k6 t1 a' v
delete p;4 I. L6 c$ H# N% ~, S7 G
}
* M4 b d! h# \7 x top = NULL;+ n/ l1 f* n# N+ k' A" [; N( b$ _
}( K; n1 B* n% D
+ i$ ^5 ^8 n2 g9 |0 J, q ^template <class T>
6 l% z6 _3 J, h! J; ]bool LinkedStack<T>::isEmpty()
; w% z/ r# O1 A0 H{
4 W: r. g1 m- ?. b1 u5 K return top == NULL;9 `2 h. ~. a! y$ h; e; I7 ~* S
}
7 k* @% l# @: m2 U5 H$ e
9 z% N! J) X- ?6 D+ m# ftemplate <class T>" c9 [7 G v5 m2 k: [
void LinkedStack<T>::push(T x)2 j' A$ Y& Y1 k! k( @
{0 k6 w {5 w, M# t
top = new Node<T>(x,top);! _; d- z2 D0 I( V$ g; n
}
& F) Y/ h, T# A& ^, p
* P7 Z( u! a9 ~ S. N: n: ktemplate <class T>" r0 t5 q' P0 P5 u2 \) u
T LinkedStack<T>::pop()0 b6 z% s e& N, x0 O2 a% O
{
* w8 y0 d, o9 e) r5 |9 n. I4 {# E0 R( s3 J if(!isEmpty())& T0 H2 G: a6 Z1 `: M& ] ]6 h$ X
{& U, F% B" [* @5 x- P3 e) _9 C' k
T x = top->data;
2 h5 a- }0 `' ]+ s7 { Node<T> *p = top;
n" f! _ p: |3 R. B2 u top = top->next;
6 V- H: [+ V2 X3 L delete p;5 \! J, Q7 n' E$ n; K; t
return x;4 h [9 y9 {% ]! l
}
# K$ f, m7 x+ i3 r; }- S throw "空栈,不能执行出栈操作";" `3 R6 E# A% R |3 `; t
}+ R2 I& b$ V! I5 m6 ?( B; x
. d$ A( u; X3 h+ w/ b
template <class T>; t! `8 V* m/ m( E
T LinkedStack<T>::get()
/ D7 `( P0 S* `+ r{
P9 `# z- b4 r& S. } if(!isEmpty())
7 {2 v5 N+ m8 M {
# |( w% [0 b+ ]( ?, l) p5 E3 Q return top->data;/ h8 `$ Y5 g' `# A/ _. N
}; Q/ s$ B3 Q3 a
throw "空栈,不能获得栈顶元素";
3 ^$ Y! C+ O. F/ K7 G5 h2 |, J, u}
1 ]9 K( i7 @ H$ g, l' x" ]* n2 G' f+ X- N
char * toPostfix(char *expstr)
8 ~6 X5 c# x4 F: ]$ b{7 t C1 n; [9 B
LinkedStack<char> stack;% r" a3 k- _7 H
char *postfix = new char[strlen(expstr)*2];
3 G6 L% |9 ~' K4 k% Y int i=0;/ p3 D5 n: }' @6 X
int j=0;
- S( I$ U5 p; K7 g; f char out ;( w; O" L1 `+ ?6 d5 ^( {
while(expstr[i]!='\0')) ?/ }/ G3 p, V. s; |3 g& j9 F& F
{
: n d* C3 j( c switch(expstr[i])/ l8 ~2 ]8 q$ v/ E+ s
{
; V3 b1 Y. t% n. a7 v9 N( r case'+':
5 _, W$ [! U' W# J& S1 S7 R& n case'-':
0 O# l; o; @# K while(!stack.isEmpty()&&stack.get()!='(')7 {5 P6 o1 N" R- |4 E( f
{9 k( ^, x3 T+ b* ]1 h. F- X* ]
postfix[j++] = stack.pop();
) {; P& D5 P/ m/ {- z }
2 V; h; `- }* U l% W; _ stack.push(expstr[i++]);+ o0 ^+ t* i: P( V# M
break;5 r3 i3 ?( a7 }! m& n2 O5 I% k- ~ e
case'*':
, E+ p- b8 c- i9 ]- v. m case'/':. L& X( {5 r5 S" S7 D l* ^+ @
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))' ?- P6 p! D. l3 Y! Y) B( ]5 O
{
) \! P, {7 g1 b0 }# H6 Q postfix[j++] = stack.pop();! n7 H' q* I9 S! k. b: K! k2 I" R# y! I
}9 n/ p* ^6 R C- F7 p
stack.push(expstr[i++]);
3 U: M- u; c4 ^0 c% V ~2 D break;% p% U8 R$ t4 J! u! e3 @+ _
case'(':stack.push(expstr[i++]);
! M/ Q* d9 \* T6 V; [9 t+ g6 L break;
! z) x: p U1 B R case')':out = stack.pop();
, `& o# b" `; E4 M6 _0 E while(!stack.isEmpty()&&out!='(')
' F- u- `6 r7 P2 U) { {" G, v6 u* D! |/ n u
postfix[j++] = out;6 L w: g, s O* F$ T
out = stack.pop();; g0 Z j# d9 P4 C2 z% r5 A
}8 k: r) @: t: J; Y7 Z& @. S
i++;( g1 U q9 l* Q$ }
break;
0 c6 ^& T5 @5 W. f0 x+ G default:
/ \) u# _2 M, u9 t& v# \, @! L while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')% Q) k! X! F3 N# a0 h2 j
{8 `) |" m; x6 T7 H! N
postfix[j++] = expstr[i++];! f' X# d1 j$ L3 T
}
! b i1 A4 z0 q- d) Q& B postfix[j++]=' ';9 Q" ]" {8 Y" F- G; [! T" o
break;
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}9 w# c% e3 a) x" l, h0 @9 i
while(!stack.isEmpty())+ x/ o; T& l+ _$ n8 c* N+ a+ C. C
{! k6 R3 h3 p) e: d5 e8 c; L- a* H
postfix[j++]=stack.pop();9 j! Q1 K8 v. ~( R* c( A
}
3 `8 x# V3 U$ ] postfix[j]='\0';* g( r4 i! O) g
return postfix;% a. m2 `$ @: ?, C* e7 e
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0 d4 @5 h4 ^" Z9 _' g ]1 I* H- |
int value(char *postfix)
4 o$ K+ W8 @, X' Q{
4 E+ A; ?8 \1 ?0 s% ] LinkedStack<int> stack;; I3 s- s: B( r) b
int i=0;, ]7 |/ Z( p; V2 s2 u. {
int result = 0;
o: C" S4 Y8 j" S while(postfix[i]!='\0')
" [! i8 @5 m# t) G+ P {+ H4 J8 z0 \, i* q: \
if(postfix[i]>='0'&&postfix[i]<='9')
% {- s4 a% H) u. [5 n9 e {0 L4 m3 Z& |5 D# L% K
result = 0;# l3 K- A9 ^1 L9 Y! c f! r, B
while(postfix[i]!=' ')3 h$ h; a, d7 V/ x7 u% {, M
{
4 T$ S2 z( ]2 x. \/ e0 L7 p+ \ result = result*10+postfix[i++]-'0';' b$ O: ~" H( @( L! H2 \6 X
}
5 f' m0 T* ?$ Q# ?8 a7 f i++;
" E4 m% f) a! P6 g) x stack.push(result);
, i/ M3 ]& Q( W }
* s! l u1 Z7 ~( e9 a else4 l) K" {( Q- o9 `+ b8 C& l
{
* _6 D0 Y! |1 M; {: s s if(postfix[i]!=' ')
9 X4 ?4 d& ?9 `8 P9 F6 ^/ x {
/ p* U- C8 M% P int y = stack.pop();! j6 _# y t6 r" F/ g
int x = stack.pop();
# [* T* q& [. X switch(postfix[i])2 y- N; Y* {8 j5 M# b' ]. W% u" _: E% L
{
4 e3 |5 Y6 K/ S( y2 Q case'+':result = x + y;
@0 x8 x. O4 r5 B6 X# _ break;$ ^/ H0 v% o) ? d& E" }" [
case'-':result = x - y;
k2 b1 Z( J- R% Y) t# C break;
- X: t5 X& O. {/ D! n j* j- K case'*':result = x *y;
" T8 ^5 C, y/ _* i0 b: E) e" N4 ^) X break;
0 y6 B& o# @1 n& O6 a) }0 P+ R case'/':result = x / y;
4 _* Q, X n4 e5 F# n/ |2 r break;
7 Z" s+ g; @7 Y }
/ r! G" N3 y% e) T0 x: q stack.push(result);1 d0 O5 e8 i* O7 ~" m
}
; }! B4 r" i1 A9 n3 k5 N Q i++;
1 V. l8 c% k6 ~: o7 R1 ?# q, y- u }4 K& c1 e! e. [
}
* _8 p9 [* D# A, m- Q2 V& q* l return stack.pop();/ [" J/ _: S8 m9 v3 p
}
! v0 N2 Q9 @# ^, r& I4 Q1 G0 h" h! Q8 p2 I7 u* w8 n+ Y2 c$ I/ a, X
int main()0 M( A& c9 \' M8 w; P' O
{
! f7 z4 K7 o% p/ W) [( s2 S //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";( b! `* j2 r: p! m' U1 `. E* @
cout << "请输入表达式:";
& N7 {" j; |- E" a+ D //char *a ;
& a4 y# D: e7 h) b //cin >> *a;
7 F9 @* J& w" w* T, w5 A. w char expstr[20]={0};
% _0 a5 Y- n8 q* d+ F5 p4 h. J/ @ while(1)
2 C& C2 t) J9 P; @6 j' a+ U, a {8 Y& l0 T+ d- D4 _
cin>>expstr;
8 s1 v+ ] A9 Z! { char *postfix = toPostfix(expstr);! T- Z9 D8 ^8 P s) P% e' a
cout << "expstr= "<<expstr << endl;
, Y$ M: ~. c6 t: s! E" F6 D cout << "postfix= "<<postfix<<endl;( y7 M* H0 M4 z& W
cout << "value= "<<value(postfix) << endl;
! h% B$ u+ _( |7 A5 D# V. n) a5 W5 Y3 @ }6 ]9 a/ R% H1 V
return 0;. v9 f6 V( p S U: `' h3 \1 i
} |