代入以下代码,得:11,9,4,2,1,6 滑稽~' v; y. Q; S1 z, d6 V. `8 m
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#include <iostream>
; m" {5 f% t5 g, d9 |* b2 @#include <string.h>
5 N0 v& n/ |) D4 g' [. U8 pusing namespace std;
1 w% d7 f A9 \/ Xtemplate <class T>
! b. k6 r. j1 y/ z8 o* e8 yclass Node
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public:8 i) C, x: k+ }3 @( X( v
T data;/ b" {1 G' E# P6 o) `( w
Node<T> *next;
7 f% Z, U$ C, q6 N8 l& P* g' i Node()
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this->next = NULL;8 W [. _$ W% Y4 A* N# i
}
U) l$ Z$ E6 u Node(T data,Node<T> *next=NULL)9 `- o- W. j. Q. ?
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this->data = data;7 a W2 I8 g! `- e; M: v
this->next = next;' c* X W% r& x8 y
}
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) C! Q3 B1 N7 X7 P" X) J& ~* Qtemplate <class T>
0 z5 K6 q" R/ q0 S( y9 }8 r7 a4 Bclass LinkedStack
2 h! Z. y6 o' R1 m. z{
7 g' {% u/ P9 g: D. ~ gprivate:
! F Z+ B9 P4 f; X5 G- D8 M. D9 o Node<T> *top;
" ~7 b& M: }$ [# ipublic:
2 f. W; q/ g" d4 x5 l" L LinkedStack();7 i8 a1 Z) u, @, w; @) M$ J
~LinkedStack();
' H* A8 M) B7 g: }8 k5 B& U8 W bool isEmpty();
$ E" q: M2 n. @' s3 z- j, B void push(T x);
; H5 M( a9 @, k% b. F8 d, N$ V T pop();
3 Y: |- M/ i! m4 P% e+ Z0 G/ W T get();
' N# k1 e D2 H) R" R};
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( f- `3 j, `0 d" { h: Etemplate <class T>
- c3 V& w1 P' _% z; U# R0 S5 rLinkedStack<T>::LinkedStack()
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top = NULL;) Q/ `+ ~% F. k
}
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template <class T>6 }; y* A9 l7 q4 i/ m
LinkedStack<T>::~LinkedStack(), F% o& ?5 I5 e( x A- h
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Node<T> *p = top;0 C" O7 T- t+ c- O; V8 V+ z
Node<T> *q;
# ]- H( V# y1 I, \/ A, f while(p!=top)3 d& t: \4 b6 b( Y x
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q = p;
% n* d( w _' p8 h. ]8 J' W* e p = p->next;
7 j0 @$ X9 E6 ?! ~ delete p;
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top = NULL;1 E0 k3 L% q' \1 s5 L7 {1 Y
}
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template <class T>
8 U; z" @3 M! K. e1 |2 D% wbool LinkedStack<T>::isEmpty()6 x3 ~7 B$ v! j0 g
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return top == NULL;" S0 }& X2 T9 `
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template <class T>
; [' j/ o& z& }# b" a* ^) }2 Dvoid LinkedStack<T>::push(T x)6 q/ G- D6 r. g2 @+ M3 k9 q
{
" f3 n' O/ Z' I5 L% w1 P+ g6 h+ x! \ top = new Node<T>(x,top);: ]! w, t- Y( \" g( q0 Z
}
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Q' w) Y; W& ptemplate <class T>' z/ s$ ]7 F9 @& @4 t# K
T LinkedStack<T>::pop()% N$ h+ x, H, r, s0 J9 A
{! G u6 T2 l, E+ i" Q. b
if(!isEmpty())0 n: N6 n; X& O% \- \+ p, y# J! V. z
{
2 S, g% d8 _- Y8 |1 ` T T x = top->data;
6 G9 Q* N, p$ Y Node<T> *p = top;
% M- n1 |3 g+ J# T top = top->next;
) `4 Z/ q6 K+ \: } delete p;
. x: @# E+ q) C5 r! i return x;
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throw "空栈,不能执行出栈操作";: c2 h$ l& Y4 j5 R/ @' q) }
}
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- {9 R0 G) j* p* x$ m& Q6 ktemplate <class T>
3 c! _, N Q2 f: K/ I! Q- J+ QT LinkedStack<T>::get()
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if(!isEmpty())
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return top->data;
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throw "空栈,不能获得栈顶元素";$ \- [ h. f+ d& w/ p# T
}
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char * toPostfix(char *expstr): Z/ w- x* Q: `3 c3 w! @
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LinkedStack<char> stack;; ^( U: `6 ]9 e8 a. j6 q, F
char *postfix = new char[strlen(expstr)*2];, i: Y; D; N! a5 O! O! Z
int i=0;: h" O9 z' j! O3 Q j) l* | Q
int j=0;! t+ m; ?) o/ v3 \% ^
char out ;
) X6 n0 X9 r1 v while(expstr[i]!='\0')
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' ?$ J( _$ W% l ?, n switch(expstr[i])
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case'+':' n- S8 X; o5 ^' r$ v) q
case'-':# D H: F+ C+ s0 A
while(!stack.isEmpty()&&stack.get()!='('); x( t; h# B: M2 a0 d2 r; ]
{
- ]) j' W1 V* S% U3 m% s postfix[j++] = stack.pop();
; x5 n1 [' a8 N# ^ }
" [& t& w" q6 H stack.push(expstr[i++]);& f% b( W- x @1 U+ P
break;
& e2 j$ S0 c* I case'*':6 |4 U4 z9 a# I j
case'/':; k$ `- B1 M* V2 t& P- z, {6 Q
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/')); z1 x' U" O8 W ^) G0 h# Y
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postfix[j++] = stack.pop();& `7 E1 v5 m5 J8 g% `0 \
}
2 I7 i. j: `4 b stack.push(expstr[i++]);2 j7 ~" b# n. }0 N4 i7 \
break;; R* c( f/ R- q& q. H* v5 @
case'(':stack.push(expstr[i++]);
4 D( m9 v! P+ n, X3 ?* _/ S7 Q: e break;& c2 V3 l% y4 ~, O5 `
case')':out = stack.pop();
3 c# x& [8 ]2 V# I5 m while(!stack.isEmpty()&&out!='(')
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postfix[j++] = out;1 U& }: W7 O: f' ^ Z
out = stack.pop();- _' @, b& x6 u# R) T, H
}! M+ i+ r& S `
i++;
7 U8 i7 [; d0 o7 @8 Z2 d break;. x \/ c9 Z- G) S+ n
default:3 f8 L' o; Q2 ^. \1 y& w
while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')$ Y; C+ F" p/ N& L; t
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postfix[j++] = expstr[i++];" e. w: S5 @6 L1 T# W! M
}
* J1 `! H$ q0 d1 {9 o# ?8 J3 ] postfix[j++]=' ';
+ ~! Z* c/ ^2 d6 U! J break;7 I3 c9 }6 I I/ X/ e% H' I2 ~* X
}
' l0 Z! t9 H4 ?- O }
* Y }( q2 O6 C! O! L7 w while(!stack.isEmpty())
6 O' ~/ s& K( e. S$ A8 L4 { {
- J4 g. g8 x) V- j* T8 _ postfix[j++]=stack.pop();
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postfix[j]='\0';% {4 c! k! I Y+ Z
return postfix;3 ?! F" B9 H# z- ^
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5 ~ \- G* i6 I9 q: y6 g8 Hint value(char *postfix)
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LinkedStack<int> stack;* f# `* C$ z7 f6 D, W
int i=0;
( c! s9 _8 A+ k2 c3 W: l) K int result = 0;
- q; S- x2 M) }' _! ^ while(postfix[i]!='\0')
( \* j; A) ~9 l i! t1 O; {4 f {
! U, b4 C5 g# S8 `/ n if(postfix[i]>='0'&&postfix[i]<='9')
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result = 0;$ i3 c+ o# L$ S u
while(postfix[i]!=' ')( ~9 P: a X+ o. H
{
" _, k7 g6 W Y# d/ n- J result = result*10+postfix[i++]-'0';
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i++;
% D: f8 a( r7 W% r5 } c% n stack.push(result);$ E( M9 W6 p& m5 |' p! w! @- y
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else
) Q$ f1 k# i* e0 z {
2 J" U" ^! ~7 ^6 j$ y3 Z( E if(postfix[i]!=' ')
% G( M' f1 V) |5 w) Y# S( S( x {
+ C9 o$ j! ~, l3 h; `7 c- o int y = stack.pop();
5 |) l, D- P" q, M& q$ A5 l9 o int x = stack.pop();0 Q: [9 D: P+ K. w& B2 }5 ]4 Z
switch(postfix[i])+ F; q0 t" d! a* I: \
{
* @' v5 C0 k3 v% h* w case'+':result = x + y;, |! v" J! p6 @ {" Y
break;
9 x/ h& D; [" |7 E* q1 f& `9 R. ~ case'-':result = x - y;/ P; R1 ?. p8 P
break;
1 K- x' G! J0 g case'*':result = x *y;: i8 F6 ]1 z0 {0 }8 O
break;
4 Q" Y; N8 ?% m7 a" @ case'/':result = x / y;
& t, P( K* }( X( i, P break;9 t: Y$ L$ `8 k. T# b# C- z
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stack.push(result);7 a/ N* c" O0 i6 ?7 R
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i++;
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! D1 W/ x0 s- s+ q! g8 k }
5 i% J" \" U0 R8 v8 H) p return stack.pop();
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int main()
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//char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
8 b0 T; J i" U: @ cout << "请输入表达式:";
7 b8 y. U s: s* f6 |7 W //char *a ;
; o( }7 h+ d' a9 m! T7 T7 k //cin >> *a;3 @6 h. D4 `; H
char expstr[20]={0};
: [1 @% G/ M) V while(1)) o' _/ a) p0 A2 k0 r
{
) ?. L! a: e& N3 X cin>>expstr;6 H3 F* D! K( T1 G
char *postfix = toPostfix(expstr);4 p$ d; k/ b2 k5 g: }
cout << "expstr= "<<expstr << endl;
9 `$ g9 G# v4 m, t* L cout << "postfix= "<<postfix<<endl;
7 w1 _: Z9 j6 t$ B2 E' L7 m cout << "value= "<<value(postfix) << endl;4 Q0 X" w j; u0 ~
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return 0;7 {% Q- E( X+ f' |2 Q5 ]3 B6 W
} |