代入以下代码,得:11,9,4,2,1,6 滑稽~$ h# v) t8 w9 a$ ?$ d* ^
" R) g. ~% D0 c O( @. O) v#include <iostream>3 }) c4 w7 a. }% V' K7 [( g
#include <string.h>
) n4 j" w; M+ j" A( U7 eusing namespace std;
8 y4 N/ [5 q$ F1 `' etemplate <class T>
- |: H X2 ]6 `; ^# B- oclass Node
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public:7 I7 y! E5 K- b- c; Z3 E/ o
T data;% U7 u( p5 W( i6 R* u
Node<T> *next;
8 U. }- a3 [/ x* a( x5 T Node()
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this->next = NULL;5 K- ]7 T. d5 b& ^7 r
}
3 y2 G3 U8 j. S- [$ ~( s3 {+ a Node(T data,Node<T> *next=NULL)
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this->data = data;7 o6 D) e2 a% i/ r. I
this->next = next;9 _8 |- ^! n' s' t g. P! m, C9 \
}
# Q/ P. E0 d4 _( {};
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template <class T>
4 b( ?+ ~3 C3 K8 x$ C0 S0 n8 bclass LinkedStack
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private:) n( M6 G: z, K9 W+ @
Node<T> *top;( h7 i- S: j* M' r
public:$ ?, ~ T8 O7 o9 i9 I. Z' O
LinkedStack();
( O( g* ~2 Q$ y& A ~LinkedStack();& r. r- E6 [' ]) Z
bool isEmpty();: P0 u$ o( f2 v+ C; m9 c
void push(T x);! N1 X, Y: l5 \% J7 r) O
T pop();
0 v0 M. l: s# O$ ^* F- C5 i T get();) I: p. a; I2 |1 P, o
};
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template <class T>
* T# Q9 |. s6 }& x Y4 SLinkedStack<T>::LinkedStack()
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top = NULL;* e" A+ c4 M4 ?5 K! b: A8 H4 S, W* c& G* }
}
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2 H& ~) @6 q2 ~, q. q6 ]' P2 ^; mtemplate <class T>3 _2 n9 u/ L; t% X, v0 q" R
LinkedStack<T>::~LinkedStack()) u6 X1 v, b8 \3 J
{
8 ^! [, Z7 r+ A( a8 | Node<T> *p = top;
* v# {$ K+ R( F3 b- f0 L Node<T> *q;* ^& |& N& e" |! Y5 A
while(p!=top)
4 C0 J. g- c$ s" ^) l! r {
# ^7 R( T {# T, X/ s q = p;
* W, y0 d8 O1 y. k p = p->next;1 o1 c; L; J6 K5 X0 g
delete p;- Q8 v/ \+ m0 b! E% M2 d
}
0 }1 m2 R4 ]3 o top = NULL;; |( P b) V! }; z8 U
}
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template <class T>9 r( T6 I- ]; s0 R" `/ w5 K
bool LinkedStack<T>::isEmpty()
& u0 u# I7 y: T- K2 {7 x{
# a |- \4 L5 V6 H) S3 ` return top == NULL;! x1 s, B+ g* Z+ K d
}9 ]1 V. W: B9 j
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template <class T>
9 {5 c' Z. l cvoid LinkedStack<T>::push(T x)
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top = new Node<T>(x,top);
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template <class T>
; r$ M% Q5 w* w8 t: R8 CT LinkedStack<T>::pop()
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if(!isEmpty())
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T x = top->data;
1 r& H( H( l7 ~( {8 ~% V* w Node<T> *p = top;
2 }' B1 M; y, w7 f# F6 \2 t top = top->next;
4 t& ?6 ?8 H2 V delete p;
( S2 Q& ]" v5 ^& D6 ]/ q return x;
& Z" R3 B+ U2 k* z1 X }
+ c' a% g7 p8 y! E) p throw "空栈,不能执行出栈操作";2 W% e* @$ U% U: Q( b6 T- j. T
}
* k4 W! U m! J
$ E* F( v! z' T3 D9 Ytemplate <class T>5 k- f* q- |& R: i' V
T LinkedStack<T>::get()6 p4 p& z, g; H/ h
{& i& S6 @( y8 e: d* e4 v5 @3 A
if(!isEmpty())
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. Z7 \# h) W& [# |9 u2 } return top->data;! [+ U q* a6 B1 e
}- `- m$ {# P9 ]2 j$ S) ]* _# W
throw "空栈,不能获得栈顶元素";
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char * toPostfix(char *expstr)
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LinkedStack<char> stack;
# E4 \3 T) C$ P% x" a- @: D7 P char *postfix = new char[strlen(expstr)*2];
) G L* W1 M" f) ?( ?9 _ int i=0;8 L' \5 a2 G! t/ S
int j=0;4 C- _" @# R% N! x3 Y, _9 q! t
char out ;
1 \0 Z1 ]6 y' P# |7 D4 [- Q5 N/ b while(expstr[i]!='\0')
' [ b7 f4 x6 y4 c {
6 T( S8 I! p( u. M switch(expstr[i]). e# {9 C' b" t( {8 H7 Q
{
9 \9 x3 A% ?1 w, ]) }) K case'+':/ g& [, F4 K: H
case'-':4 p/ C& ~, L/ V
while(!stack.isEmpty()&&stack.get()!='(')
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postfix[j++] = stack.pop();) T: B' \: d0 L) h# `5 N* d
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stack.push(expstr[i++]);4 z( P' j/ _2 O9 l4 N, B
break;
7 Z3 g; a% y" l case'*':
0 g1 _% p: M* w) W( P! T* S7 } case'/':
* y, X5 E( N1 m while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/')): `3 n/ T! d8 U, t) e; w/ W
{) h+ \, e$ h7 F8 I
postfix[j++] = stack.pop();
7 |; K! n ?% N3 u }
4 T/ Z2 G, `) p8 ]" p% S4 a stack.push(expstr[i++]);
5 B2 h: R1 w- U8 N9 n6 Y) l0 N! `9 Q break;
( U6 k' ]% O. X0 J5 ^1 X |2 x case'(':stack.push(expstr[i++]);
$ J( b9 S5 i- B# o& u break;
0 B l* {. U9 F* `; z case')':out = stack.pop();
8 h) [% s+ i t% r2 z while(!stack.isEmpty()&&out!='(')
/ E2 }3 [+ y) H {
5 a) f' S- R/ w& ^ postfix[j++] = out;
- q/ G- y. e' U# w: e2 X, R out = stack.pop();: i; K- P# P8 N2 X4 P$ J
}1 }: k5 J, Q1 B6 H2 B* F* S2 V' y
i++;
5 \6 s( x+ x. Q8 k6 B7 o( i" ~ break;& A# i+ g0 b- b" W7 }
default:
$ E( u1 o ~% N' i0 h while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')
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postfix[j++] = expstr[i++];
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postfix[j++]=' ';4 X7 _# e4 j; \/ s" q8 j
break;
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while(!stack.isEmpty())2 m! c$ Q: X1 B" j
{
% |+ C& [% x+ a$ E# E, P9 ~ postfix[j++]=stack.pop();% o" V* p5 B, { }2 ~6 S
}
! m- q: k: }, n postfix[j]='\0';
\9 b. z' i7 Y$ k. Z' ~% m return postfix;# j% K/ l7 A% a6 y/ a
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int value(char *postfix)
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- p; x; W7 C6 ~ LinkedStack<int> stack;
6 ?0 g# p9 ]* i2 Z int i=0;6 R* o0 {" ~7 h& D4 Y5 z, x% t
int result = 0;+ V/ K# A8 Q) ?; E; J8 P" D- q
while(postfix[i]!='\0')
* e* m. D! i7 o8 ^: P" \ {
: f7 M8 |( K: F) z& [5 y# s if(postfix[i]>='0'&&postfix[i]<='9')$ b" h S* [% Y
{
4 ~9 x9 ?$ L$ e$ Z8 B, B result = 0;
+ f- H& m# J+ W0 U- ~, l, w while(postfix[i]!=' ')1 {1 J% ?, X( d' n& P# n9 z
{
$ ~- g, t U. m5 @' I% Z' |6 } result = result*10+postfix[i++]-'0';
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i++;* Y- M3 |8 v# I. r% D
stack.push(result);
+ _( P6 \6 Y. K. p0 w8 d/ w# Q. y }. {) {$ d2 ~$ e+ e$ }- @
else( f9 w6 @$ o# r( o; v' ^* ~" g0 g, T
{
% E) j, w9 P5 n% U s! Q2 W if(postfix[i]!=' ')6 j3 Y6 V$ i% u1 X2 ^
{ A, x- \4 {% U' O {' _% x1 u
int y = stack.pop();- j8 g: r; B4 N5 g8 u% z) p: ]
int x = stack.pop();; W& v2 h2 f7 r5 I- P7 \' r6 l+ Q
switch(postfix[i]). Q7 M" R* Q; |) o
{* ~8 n* B, K, T" a( a
case'+':result = x + y;
) E! d. L8 \/ r1 ~/ S }# J' l9 a4 Z% ^ break;% |+ ]/ ~6 a/ O* m' q# W( T9 J
case'-':result = x - y;: H, f/ J8 o, C6 Q
break;
7 q i- s8 p1 W, j, p3 \4 o case'*':result = x *y;
3 ?. I, j3 U' q+ r7 t, y1 ]7 u+ V break;' e! P M! ]0 _! R
case'/':result = x / y;5 @( D8 J/ z& P w+ \& T6 A4 j
break;
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stack.push(result);
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i++;
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" F# S2 R4 ^% v, i( j7 }7 p3 U }
# @3 @: f6 \! V( |- a; c: e( I* E/ b/ N return stack.pop();
% }3 i) \9 _. a6 j6 k: Z}
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int main()
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//char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
5 H6 e, b8 O" k$ Y2 b7 | cout << "请输入表达式:";: J6 g5 n( A0 \8 C
//char *a ;
2 q! \* _0 _3 X6 Q% W //cin >> *a;
' i5 t9 L7 I% c4 j& \ char expstr[20]={0};3 c- R: d& p, N
while(1)
" I3 Z, y3 t' e6 b {
# D8 C Q# _" n7 R, h cin>>expstr;
3 L, ?3 A2 M% y r& v; H; B$ B char *postfix = toPostfix(expstr);9 ~& C; m7 b O$ l
cout << "expstr= "<<expstr << endl;
& T2 `& o* ]6 w! {! r cout << "postfix= "<<postfix<<endl;
( L) ^# y# A( k+ X7 f; c/ @6 ` cout << "value= "<<value(postfix) << endl;, y6 v) k3 E) k) t* l
} }7 K0 \# Y& K% v
return 0;! P$ u( z9 @5 H# d, X
} |