代入以下代码,得:11,9,4,2,1,6 滑稽~* `& s& e, O# G: j
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#include <iostream>
! ]4 B# T0 O9 u; n#include <string.h>
' ^7 ^' t. q, [using namespace std;. h F8 d$ B+ D. ~- j/ [
template <class T>5 S5 D/ s: @' u6 D# r/ Z5 d
class Node+ E4 z6 Q$ I9 w: n
{
8 Y s# {# a; upublic:& R8 h/ m1 Y* B* m) y' \
T data;
2 {, ^+ u2 b+ u* g1 G Node<T> *next;; m; u$ y8 y. P$ ^" ~ X, ~6 X
Node()
/ u$ I" U1 \9 v2 m# z4 ? {
6 Q+ U; r2 F, U/ ?6 X this->next = NULL;
) @) O+ }6 J- c: q7 p }
( p- \2 B6 H1 l3 o2 Q Node(T data,Node<T> *next=NULL)% ^; X1 p+ I! l0 e) w: P2 [: d u
{9 N' m5 [2 M; S8 H9 C* q# M# z
this->data = data;7 O O* s! e$ E0 c8 f: e
this->next = next;- }+ q( J9 D8 R/ O( k7 s$ i% m
}
+ M6 j. G @4 D$ I) L( W};
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template <class T>
+ Y+ B0 M( u7 [4 I9 S3 g) dclass LinkedStack
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private:
6 U4 p6 W' i) _6 e3 t# ^ Node<T> *top;; O y2 {1 J4 X1 t
public:" l+ @5 o2 `/ B1 V, o6 d
LinkedStack();
" g1 e D3 |' d ~LinkedStack();
; x; Q& a; z% d7 s0 o9 H bool isEmpty();
+ Y' Q: j" R W" ^0 y& Z0 U1 w- t- ?' F void push(T x);
0 a. N% Q5 Q/ B9 S3 t" |0 ` T pop();
) U2 e7 k: f6 m! H T get();
# b" R* K) v' L J- J6 p};
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template <class T>
2 W3 Y8 o# M% E, gLinkedStack<T>::LinkedStack()" {7 o; [% L5 D4 ~3 l- |
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top = NULL;
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% G* N" d) V+ I) O) q, S8 qtemplate <class T>
. s& d( ~2 A- p/ m4 ]& H7 SLinkedStack<T>::~LinkedStack()2 M1 F0 M( ]5 O
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Node<T> *p = top;5 ^9 j2 n4 ^1 K/ u
Node<T> *q;5 m' x3 L0 n2 F6 f
while(p!=top)
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q = p;
- K' M! n- W0 Z' u- ?/ d K% U p = p->next;
: C" {/ W5 F% V, f( g, Q) { delete p;
1 L$ S- w0 m% B1 n7 ]' y }
$ Q* i) j( r+ [3 e/ T8 T1 p top = NULL;! k* j$ E* C2 n0 i3 u1 O* u
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template <class T>9 Z- ~, Q6 z, |9 b3 |
bool LinkedStack<T>::isEmpty()
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return top == NULL;; V& k- ^% n2 C: h
}
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template <class T>& o9 A$ }7 b, v+ d
void LinkedStack<T>::push(T x): l' E9 H" S! T' B! o
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top = new Node<T>(x,top);; ^4 C, V1 C0 V/ u
}
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template <class T>- x9 q2 b; R( {( h2 G$ W
T LinkedStack<T>::pop()
; z. X8 y- V8 r{
* J: _/ j% v0 r0 ^( D# v6 o/ W% v if(!isEmpty())
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T x = top->data;* G* s8 X: \. M$ {4 m: u
Node<T> *p = top;
( E/ f$ a; R, \+ n8 h top = top->next;
0 D F% y& G( o- l% j delete p;
& J9 i1 M* x# ~- X return x;: z6 D E& L6 E9 i# W. j
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throw "空栈,不能执行出栈操作";
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) B8 y" l& B2 Q: I0 o1 itemplate <class T>
0 Z5 R0 b7 }; N- M; ?% t: O" }9 sT LinkedStack<T>::get()9 ^5 b3 P: @8 J
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if(!isEmpty())+ M& ?' |) v( u% h* E
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return top->data;
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throw "空栈,不能获得栈顶元素";
9 {% L8 H2 [) g/ i}
- b; K: P3 G# D1 s+ {
: W0 w5 b! g _, g: m* Jchar * toPostfix(char *expstr)! b0 [/ ]9 V3 P7 ^
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LinkedStack<char> stack;
1 U! z' ]: G# R. ^ char *postfix = new char[strlen(expstr)*2];; e" V' `. V; ?5 P
int i=0;
) a6 s' |7 ]- O: T! O int j=0;5 l k8 m% g$ n/ i B
char out ;
4 g( F/ [) q5 D2 d; l$ C% f4 D while(expstr[i]!='\0')
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switch(expstr[i])
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case'+':
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while(!stack.isEmpty()&&stack.get()!='(')5 P$ {3 i: r8 j' _/ {
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postfix[j++] = stack.pop();" r; N; k; t! i; A8 E
}1 A Z4 r9 Q4 |4 K( W0 M( \
stack.push(expstr[i++]);8 R* s) ^( T B0 w% ^# `2 v& a
break;
4 h& Y7 b2 H8 I case'*':- f! e W/ s) B3 P
case'/':% N( E- ^7 Q/ p) A: t
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/')), [# t% H2 c$ n8 I$ G
{
3 }) }5 y' W: n* c4 ]6 v5 h+ w postfix[j++] = stack.pop();
; v! X1 R- \$ \) h P }
# \" ]1 j7 l. M2 V3 Y+ | stack.push(expstr[i++]);
- R0 D* j; w, Q; E2 D# f break;! n2 A9 `+ i1 W1 g; q
case'(':stack.push(expstr[i++]);7 j! H8 n! O- w( T# J8 F9 \
break;4 {' q# ?. P" Q) _5 H+ b
case')':out = stack.pop();
' o. T- V+ Q1 l- R& h/ Y' [ while(!stack.isEmpty()&&out!='(')( P' z& M1 `3 i
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postfix[j++] = out;
0 ?, k3 j5 }( W4 w/ \ out = stack.pop();
5 S9 N T; Y8 u0 J" x }
; \4 T" g! D% ?* I$ [ d( d5 R i++;
, }0 b- P; C9 T0 i# f/ p) C break;" p% E' E q( @6 B* b
default:
5 k5 @8 T1 n; C while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')
, a* i0 U7 E8 Y$ Y t {
( p. V* |6 m4 \% P1 ~6 e postfix[j++] = expstr[i++];% z2 V. X9 K2 ^& ]" h
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postfix[j++]=' ';
( ~0 Y- \% I& Z# B1 z2 C+ z break;( q+ I. x0 Y" i P1 n' @7 i
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while(!stack.isEmpty())4 r6 w' m' M! Y0 y
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postfix[j++]=stack.pop();
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" k, z% y6 l) M8 m- X4 D7 v9 F postfix[j]='\0';
* D0 A! d( I' U1 A3 p- D return postfix;- _2 w5 s) I" E! M
}
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int value(char *postfix)' p& W+ p/ q* h8 [
{
7 T5 [# ~* ?9 q$ B% U0 D( K LinkedStack<int> stack;
) N$ B7 k- X$ q int i=0;
9 R [9 \* C' B- P w int result = 0;" o1 V$ A- a( [3 x9 g
while(postfix[i]!='\0')
4 s# s$ @% [$ C; j' o$ }, | {
3 e6 g+ z* h, R" w$ n5 S' u if(postfix[i]>='0'&&postfix[i]<='9')- z* z0 R" q9 R: N B0 f
{
0 ~. D( y$ Z/ M+ u N" h result = 0;
$ U) H4 t+ g) w8 d- m. ^: @ while(postfix[i]!=' ')
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result = result*10+postfix[i++]-'0';
8 v# i1 Y1 x- R2 S5 c }
4 M# a, @9 c" I1 q$ f* @; w7 C1 E i++;
5 j, g5 n# t: }6 k( J' n1 H0 ] stack.push(result);
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else; _% n2 ]" d3 C# F1 F; v9 a
{
& }% M' q1 s1 t$ K/ ?3 H if(postfix[i]!=' ')
5 A7 u1 T. o1 C {
" ~! Z, r6 m+ |$ C int y = stack.pop();
1 R/ c" {, R* v* I) w) l' X7 \, @2 A. [ int x = stack.pop();
3 P; V' N4 d9 g: k, Q" r* a switch(postfix[i])% Z I0 B$ g9 r+ r& L
{
6 U1 a- f) H ` case'+':result = x + y;; w/ ?) M4 m& G. `6 m/ s# o
break;
1 e: l6 J$ {: X4 C case'-':result = x - y;
- S8 Q7 l* [9 Q0 D break;; |8 t- ^7 _ y. U' Z- z
case'*':result = x *y;
1 S2 S* S! z4 _" [, m: N* D3 { break;
" J+ k3 ]' H2 p% H Z case'/':result = x / y;$ r; H6 V/ f3 s6 C( n
break;
( b- K3 i! y: E6 h }
" h0 P" T' S9 Z3 h% M$ G K% ` stack.push(result);
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i++;
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. D6 W* @4 |4 I/ x/ X }
2 U, Q+ ]+ ~" M9 ^" W | return stack.pop();% }- e* T/ z) n( ?1 V: o. ]
}! _1 q! f7 W9 K X: w+ g
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int main()* t9 L: L# l( X. h0 _, Z
{
" L4 Y# X# t5 g //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";, {% m' z4 {: Y; ^+ z
cout << "请输入表达式:";- N7 n4 o" J- H: G2 \+ X, w
//char *a ;
4 j. t) r7 j& l% X: i //cin >> *a;
) [, m4 P9 H% b char expstr[20]={0};
: W6 n/ S1 A/ n! z4 F5 h& v while(1)
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cin>>expstr;
9 d2 K- a9 Z( U7 Y char *postfix = toPostfix(expstr);
! G$ i7 f8 y7 t3 T% m, @2 M! `+ | cout << "expstr= "<<expstr << endl;$ y) e" w' m% o5 T" g" e* J$ r
cout << "postfix= "<<postfix<<endl;& v0 d4 m: R4 J) @4 Y
cout << "value= "<<value(postfix) << endl;4 K1 X, A% w! c8 w2 A. E* h
}
. C$ f p$ S0 P6 i return 0;( U q7 b+ g- d) i' S
} |