0 m: t; K* r% f8 s代入以下代码,得:11,9,4,2,1,6 滑稽~0 X) ?+ P" `! K( k" o
! F- t( W9 d: x1 j% S# m#include <iostream>
2 f! K0 J- ]. G#include <string.h>/ O9 O8 _" o/ M8 e* _% E
using namespace std;# J- v, i E, ]. K2 q5 J' L
template <class T>& O8 t P" j/ S$ r2 r: d
class Node
/ |' q$ F, @! a3 `{
8 m {, X' ^. ^, x" B) h4 Ppublic:
) W8 x# L* N' K) H- U. t( ^+ i T data;
) `8 ]/ r" o* y5 j6 |' G Y( b Node<T> *next;6 c4 t( i/ B$ |; }" J
Node()' A3 G9 ?, k6 X8 i* a2 k- ?" h
{8 {+ c# H; c1 B
this->next = NULL;
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: z+ l( s# K% ]1 H5 w) L. |/ X! ^1 N! P( t Node(T data,Node<T> *next=NULL)
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this->data = data;9 o- R6 s. z! b, V# D
this->next = next;) p; m+ |% b, \2 J$ u
}% K3 [: r1 f, \+ O& E1 T
}; ~1 g. |5 e# \3 i# k, T" A3 N) \6 b
& O8 X8 x. y; s# }template <class T>
" ^' g. a T: o! c" vclass LinkedStack! L2 ^( ]9 I9 w% b
{
9 s( n0 I: Q; k4 ^private:( k* p1 U. w; O) |
Node<T> *top;
9 I6 w. e2 Y; Q- a" K! zpublic:
7 { C2 ^- _, a% z' Y! [ LinkedStack();
9 q3 W) D# Q; h @, @0 e ~LinkedStack();: l( h9 F5 }) `
bool isEmpty();# M) U6 } O6 l- G
void push(T x);' ? e# b3 z1 V2 N
T pop();
$ {& a9 ^5 U- n# V T get();
3 I& Q: @' X* u! l$ d& P};
" M: [: m' @0 X& Y9 h$ Y
% R2 X6 c0 O) ^4 |, itemplate <class T>2 g% `- K8 N! d# w+ N& \
LinkedStack<T>::LinkedStack()$ b/ V) ~+ i. Q. o; o) l9 c
{: C j1 f' i, k9 _4 s+ h1 q0 L/ B
top = NULL;
; U8 P( }! I- g) i$ u1 W. R! `}
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template <class T>
# f) N+ D1 t* e3 sLinkedStack<T>::~LinkedStack()
^" `0 I t( U4 c7 Z$ J2 z{
8 T Y ^! U: j4 f Node<T> *p = top;
6 r: n" V7 s# S/ { Node<T> *q;# b3 \4 r9 ]* h# E9 p0 G
while(p!=top)
) g4 \. X! \9 i6 ]9 R$ J {
& h, q; \4 x4 A1 \1 e. y9 R3 @ q = p;) Q* H2 Z% ?% {# g
p = p->next;' N; k- a( j0 y& A
delete p;
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top = NULL;1 `8 n6 \- ?! u" E& N
}
6 r# s0 b! e* n9 j4 i9 M; f
5 L* p* U. L% W5 r( }+ s) {8 mtemplate <class T>
( U2 Z" ~0 n6 K3 K# |bool LinkedStack<T>::isEmpty()& |6 B2 H& T: T1 |# P; ~3 Y# b) i k
{
1 S! |5 b8 \. c7 f8 o$ r return top == NULL;
7 d' Z5 {) S0 U6 u' S7 }2 |}' _# |* z- v, _0 M O8 {% w
6 J$ { @6 o, r$ qtemplate <class T>
2 e% e& e( E6 a% Hvoid LinkedStack<T>::push(T x)# @0 ?/ f. V- I( u3 M# Y
{
6 Y2 t* q& D7 M# k& j* \0 J* s top = new Node<T>(x,top);
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2 j/ p. S5 y7 w- J; o* Ptemplate <class T>" Y4 W: |7 m6 T/ B( Z7 ^4 |
T LinkedStack<T>::pop()
. n8 } b# Q: [( r" j, w{
# s" A* q Y; r+ l if(!isEmpty())# V- k* k% ?0 i2 ?& H
{ X; i6 J* j8 s5 q2 k
T x = top->data;- A' L& T& J$ o( ~( p& `
Node<T> *p = top;# T' k2 \& n* V9 m% }% v; f
top = top->next;
! N2 X) _1 z/ X! X delete p;
3 r7 ~$ N+ P) s% ^! b4 D return x;
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throw "空栈,不能执行出栈操作";
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+ K- U+ ?6 S' T/ y) h
template <class T> F2 e1 @: r% G1 l M
T LinkedStack<T>::get()
+ C: f2 D( G; P: g- ~6 `{
' x {& |4 O' W) o! U2 D if(!isEmpty())
. X+ k( k' V: t1 K5 u9 ^+ F# I {
1 R* E# J: l) b7 F: N8 } return top->data;3 U1 h9 ]( f! t
}8 m6 Z' Q3 S$ R6 V3 v
throw "空栈,不能获得栈顶元素";
# R! P; e9 O8 Z0 Z. ?6 L- H}) P# ^5 I& a6 n* f1 c; H
$ K: x# K( |% }char * toPostfix(char *expstr)
6 D7 k5 G; l9 V1 x3 w2 z, d u' s{, {/ r- R; _0 f t8 c
LinkedStack<char> stack;3 N' h, z& k' @3 v
char *postfix = new char[strlen(expstr)*2];
% O: Q8 M3 X, r8 ~3 N* c1 h4 A int i=0;
" A2 C# p7 k0 b( w. { int j=0;
: N. |+ c* \5 n/ n char out ;
( f9 J) c0 X9 }7 c while(expstr!='\0'): k5 z# \/ T. L; W- h t" e) l
{, V( u0 I1 { [/ Z2 f+ {0 X& [
switch(expstr)# d& {. U ]0 v l7 M8 x9 g; @
{$ d+ r5 V/ D: r& |. ^- c3 j
case'+':
: U2 S( P8 ^% ]- s" ` case'-':* R* D5 P! |# w* w: A
while(!stack.isEmpty()&&stack.get()!='(')
6 d3 y$ t6 J" y6 g: e7 p+ C {
e4 Z' n9 j, ], d postfix[j++] = stack.pop();
5 ~7 n! c! U- e1 m6 t5 X }
" f: p( M8 ^0 H( S ~ stack.push(expstr[i++]);: A3 _3 U8 Q! e& @
break;! L/ X, [7 X* g. B9 j1 [
case'*':4 U& a) c8 H( z3 t5 V; l9 o
case'/':: N) Y( o: ?: l. t5 c' R+ Y
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))9 ]- X% o. z! n6 p% x
{/ `( V) M2 t1 \' X
postfix[j++] = stack.pop();
8 u9 s$ |( d# C6 c" `- H* F* ^7 f }# q$ M% p5 O/ Z! G# G) r6 Z- b
stack.push(expstr[i++]); k3 a. v/ S3 C2 R$ z
break;6 v; p ?, B8 W, I+ l
case'(':stack.push(expstr[i++]);& m+ H ^3 h: H, {) f! H) g
break;' I- |/ a) o# }6 S( ^! i2 A" ?
case')':out = stack.pop();7 g: g% R3 u, W" ^+ G/ l3 }
while(!stack.isEmpty()&&out!='(')
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postfix[j++] = out;7 V7 i4 Z( d1 `9 {
out = stack.pop();' G1 [. v# t: O2 {3 U3 `" O
}! s+ B1 N% g: U4 ^2 c
i++;& f( X1 E; X7 W. x' V+ L" \' a' g
break;7 O' `( t/ |/ e/ E! Q
default:- ]0 }2 a* b! k3 g8 F, T! }
while(expstr>='0'&&expstr<='9'&&expstr!='\0')
3 {5 t0 f y3 I5 F' G; @ {
$ l! ~) v; v$ q3 B6 ]" c+ @7 d4 R postfix[j++] = expstr[i++];( l% b: N+ A; D: \. E6 i/ J( B9 @
}; {: h4 K# |1 Q* `+ k
postfix[j++]=' ';- x' v$ i" ?. a4 z# `3 H ]( s& \
break;
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}6 }- M$ P1 ?7 i" b+ T4 N4 r* o) h5 X
while(!stack.isEmpty()). b4 r0 I* c4 x% N; z4 Q) ^
{
2 L' t; b8 W7 B postfix[j++]=stack.pop();! t4 z, P. m+ ` d8 v
}2 `, y9 O3 w( v* D1 f# N* I4 d' A7 F
postfix[j]='\0';5 R I" V$ j0 S* E
return postfix;
) b0 x8 Q- l) B1 P. f}
% X, C7 f7 J; W
4 C! V4 ^7 X$ S* Lint value(char *postfix)+ s/ G2 G* O; U" C& t1 N0 ~/ J
{& }% k* t) V. c8 N; `4 I" |( R1 z; m
LinkedStack<int> stack;9 @3 d& e4 O" N- b# }5 a) N2 r
int i=0;
: }6 S2 ?4 }7 x% D" h$ h" r1 i) W A5 G int result = 0;
+ _- X1 S% @7 N while(postfix!='\0')7 k+ I; j; f0 [$ @4 w' E( x
{. `% v5 c. s: f$ ~7 y& L0 Q6 p7 S
if(postfix>='0'&&postfix<='9')
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result = 0;
! d3 ?+ E% v# j( Q. c- H while(postfix!=' ')2 }2 z$ N& K4 t0 M# r( H3 U
{6 _! }! M6 U+ w0 r- a3 r
result = result*10+postfix[i++]-'0';
g- E# @2 T. @ j% y" U/ R1 y6 y }- i5 C# o# s$ `) t3 W1 F9 G6 m6 K
i++;$ [& N g( U. O, M6 j& m6 x2 h, M; }
stack.push(result);
( r! @' d& w1 c/ V }
( l# p, o1 x4 I Q0 _: D' \% z# ^ else
( u( V |3 q8 g1 Y8 m+ [ {. o: ~1 F) U2 d8 S2 r: K3 r
if(postfix!=' '); t4 h( Q9 o, C# P+ X( X
{
4 V9 A0 L5 y9 H; T4 M; c int y = stack.pop();9 q$ A6 m! ?$ r* J
int x = stack.pop();
$ Z& f( H% d* {' Y: P& a! ?$ j switch(postfix)
, y5 J8 k5 ]5 G) U {
# x+ O4 {2 H( S! I case'+':result = x + y;
! u5 P* b$ b3 `% c break;& N& ~3 S3 ?- D9 ?7 U
case'-':result = x - y;
, b9 V" }+ K1 u1 n. w; o& J break;2 l9 k) e, e; {7 L0 c) I2 N
case'*':result = x *y;: t* m( i+ @5 C% R0 d
break;
- g; a8 k7 X5 Z3 R+ a case'/':result = x / y;, B* B, V6 {$ Z2 w
break;
: I5 {; \* A0 Y1 u6 l/ E) t! z }
- E9 Z, i- p% a' H5 z stack.push(result);0 v! y+ y. R% \+ w$ |
}
9 C3 H S2 d; w9 w i++;* |3 _1 O* l2 u& m$ U
}
6 r& {) S; S5 P, [# W+ M7 } }" m6 t% t# H% {
return stack.pop();4 y$ g3 Y" Q1 n3 X8 Q7 w% o( g' v9 ~
}* r& o& i1 M$ F& _0 B
; i$ m: q; F) }5 t" bint main()
2 P* Z& t6 T! u; z6 O8 j{* R% t% ^0 g1 O, e) S2 K L
//char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";+ @! z* o' T w# R- Q! h
cout << "请输入表达式:";# U O. y. B* J
//char *a ;
/ I* y: _7 d- ^9 H0 L //cin >> *a;
, W$ L" [) w; z& p$ _9 s H char expstr[20]={0};" r$ \$ |% f6 ?
while(1)7 s/ {- h1 |6 G- a
{, k; _& h+ T* N4 I3 [
cin>>expstr;
7 A. ^7 c6 g* G6 p7 c' i& K char *postfix = toPostfix(expstr);
3 S! ^( _! A& X* z2 D. m& J7 H/ N cout << "expstr= "<<expstr << endl;
- `( V; \/ N1 _3 [' ?2 _4 x cout << "postfix= "<<postfix<<endl;
* p1 m i( h4 X h+ ~+ o" _5 t cout << "value= "<<value(postfix) << endl;
3 F: f2 H4 k: j& O* D) S }' n$ i5 {' H, @' }) V
return 0;7 ~/ C# j% H; }8 ^/ q8 V; i, c! }
} |