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代入以下代码,得:11,9,4,2,1,6 滑稽~
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3 V2 x, ?! h, \% R7 I+ n0 Y/ D" ~#include <iostream>
- j5 l5 X, _: P#include <string.h>
' O. `3 C- U2 j& q8 rusing namespace std;
# r# r8 a5 ]0 S8 v& Ztemplate <class T>! N) i i, i( `% r6 ^5 K
class Node
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public:/ T1 e4 B& y2 t( F
T data;: b. C6 I; w4 \8 |( e6 i2 r8 z4 B
Node<T> *next;
1 m6 {! ^# w# [, k: U Node()
% D3 q2 p, j5 h1 S. f: ] {
$ E% k \# T2 V/ x this->next = NULL;
5 p' A u) [( t. o; Y7 {3 U5 K }
) W9 E+ k2 K4 v Node(T data,Node<T> *next=NULL)
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this->data = data;
% X0 x1 f9 K7 N8 W4 V this->next = next;
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};
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template <class T>, P1 m- m" V$ ]6 T1 P/ j' H- R ~
class LinkedStack
' K5 u4 i, p2 c" O5 A; O{
3 L) t! h1 z. D7 c: iprivate:+ w# ] d6 x; M6 L2 W6 }' [: l) m
Node<T> *top;9 ?1 r7 y$ D* Q/ o5 N7 @
public:
3 }5 ?4 G) i& f6 m LinkedStack();
, x/ m, u' E1 `3 O* Z, n ~LinkedStack();3 I' i. @. ?# H. p, g- {
bool isEmpty();
. s/ u6 T% c P8 `( Z5 | void push(T x);
4 F( I+ u3 d: H T pop();/ d+ l3 X% a3 N- O
T get();+ g$ A6 u4 }) u9 ~$ ^: O W$ s5 V
};% l2 N1 d& u8 T4 Y! G( u; `7 n
* ^# p, l. t, L2 otemplate <class T>
" f( [6 K" k' ~, `& C8 n4 yLinkedStack<T>::LinkedStack()$ O& O5 N8 d; l
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top = NULL;
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2 P% {5 q( Z, _" \
template <class T>
' R7 f$ d/ i. ]7 ILinkedStack<T>::~LinkedStack()" {* d7 X9 y# h+ f& W
{
[+ S' L( F- t4 c Node<T> *p = top;
& v2 _% V% X, v$ h0 {2 t ` Node<T> *q;
6 u. ?4 A- s5 S6 _9 G) s# Q/ l while(p!=top)
6 y+ x9 m; m+ q1 W* J2 q {
" j: C- c) O) p, ^2 e q = p;* h, w+ g1 M5 z; v4 `
p = p->next;
; U2 A. m+ p v% N delete p;
& [( H4 n7 M2 U: @ }
6 j, S6 ?7 u Z: b; s d ?2 i top = NULL;$ [+ m# \' y/ n1 ]8 B( R; J( N
}
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template <class T>6 g/ O( G+ _( i
bool LinkedStack<T>::isEmpty()1 U# a$ w% I8 R( i, ?
{# [. b U% j% W8 u+ J2 v
return top == NULL;
( v6 N/ I" t6 y- K& O: n4 m}
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* [, f7 r/ ~2 ~: T% R- U* _; {template <class T>
1 t8 h# \9 r& [0 N! V6 U( ^3 Qvoid LinkedStack<T>::push(T x)
; Q# T, f c, D8 b2 p{
6 h- V) J% D; u. W" R7 c) T top = new Node<T>(x,top);
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template <class T>
( g; o( b0 O. f, e6 ^7 E: l* _T LinkedStack<T>::pop()5 F$ R0 z( p/ j7 u- E4 x
{/ j* J$ g. [7 `& \+ f- R5 y
if(!isEmpty())
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T x = top->data;1 n/ \5 x# Z' z! L/ a
Node<T> *p = top;% y- n& B$ C l% [
top = top->next;
8 |7 H# n7 i! V9 h2 ?* i& }! K delete p;
9 X5 c% H Y* ]2 b! ~, t1 ^ return x;6 j& C; V4 k0 ]9 m
}
& a9 C9 J1 ^# Y& `# { throw "空栈,不能执行出栈操作";( W8 J& ]1 N7 W: |& Q# ^
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- ]& H( K& I) M' c* e8 A
template <class T>
6 P% _0 y+ o- Z2 p9 v2 }T LinkedStack<T>::get(); F! c6 m# Y( y [. c
{- p0 B: G5 i1 V8 P6 B
if(!isEmpty())
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return top->data;
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throw "空栈,不能获得栈顶元素";. s2 y* \. H1 m' [3 h7 t
}
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char * toPostfix(char *expstr)
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5 v1 h' O7 D* a3 h$ l LinkedStack<char> stack;
( C8 @% M1 E1 ? @ char *postfix = new char[strlen(expstr)*2];/ h, C' b* S/ t1 _9 z3 y6 B @; A4 Y
int i=0;
/ R6 n5 J( c9 p6 c6 x( ] int j=0;+ P/ t& a* G: m8 V! Q+ `- s
char out ;
B) ^) ^6 ^3 N$ \( m7 n, k6 k/ E) o while(expstr!='\0')
6 o5 _% h4 F! T8 }& X* c {
# }' k7 i' m* D; ]& ~" Q3 Y. p switch(expstr)/ i F" u( S. A' G- Y6 ^6 E
{
! Y8 Z+ {7 W! }, Y4 i6 G/ v case'+':
# F. p$ X- b, F, V* ? t case'-':; E. A0 b) y4 p( ~" _ O) y3 s \% s6 {
while(!stack.isEmpty()&&stack.get()!='(')
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postfix[j++] = stack.pop();
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stack.push(expstr[i++]);
) Z( N/ V) u# g, ^ break;0 K- `. G& O- n+ |) Q) W
case'*':
0 t) B" P9 d6 |' n3 I8 T case'/':, E9 l* L' n9 Q( x0 H8 o
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))
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postfix[j++] = stack.pop();
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stack.push(expstr[i++]);! P, f$ h; H9 D8 ~# c5 F
break;
. I/ {3 b6 g4 E/ U" }: ^ case'(':stack.push(expstr[i++]);+ g! w' N4 K- c- l; Q; v
break;2 I" S# J$ _4 c# C' ?
case')':out = stack.pop();
' K. h) p' C4 m4 S$ L# w" W while(!stack.isEmpty()&&out!='(')
" n3 x q# m/ N. a$ x! ^* F {
" J1 [4 C" X: D1 P% l/ u4 a. Y* O postfix[j++] = out;) N0 s- P9 e7 W
out = stack.pop();# G- F/ \: @3 J0 g' v2 J
}- M1 L9 B2 a$ D' j3 N
i++;
/ Y- q9 |: K& M3 A2 b; s9 O break;
! `& U) }* [! U4 I2 D4 n; ?3 l default:
. ?8 h. T, y2 ?# |% A+ ?. S) [ while(expstr>='0'&&expstr<='9'&&expstr!='\0'). V! _( o1 Q3 Q" F
{
+ e2 t" K+ m1 r& O- [' W6 b7 j U$ Y postfix[j++] = expstr[i++];/ v, a* Z; o2 n; i( w) s6 V
}
2 Q: d! A$ [: V- ?7 Q postfix[j++]=' ';
7 ~: Y& G: G' Q" U, Y E2 _% ^/ n p break;
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}0 V2 x5 ^6 H! K
while(!stack.isEmpty())
6 [- C8 T# A3 X9 U8 b {
& r" P! J9 R- i* V6 C( `+ [1 | postfix[j++]=stack.pop();, E+ ?. ` M& O
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postfix[j]='\0';5 ^* R0 o& H6 {# l# v* [9 ~' i
return postfix;, X5 |1 `% a; r q
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# v& ^+ M7 W$ Z- n$ q! y1 pint value(char *postfix); C0 l. T) F: W
{
5 V- k2 b. L s LinkedStack<int> stack;
/ y+ ?, e( E6 ], } int i=0;2 w0 ]- y' v Y% u- `
int result = 0;
/ D& J: b+ g% u: B/ v! r. ^. ] n while(postfix!='\0')+ X5 z* x0 l$ e! ?6 d. ~$ V- E
{
$ x: S8 e. l% n4 R* U, p" V2 J if(postfix>='0'&&postfix<='9')
: W8 [; A3 U% F' ]0 Z3 B {
4 E2 Z% |9 v0 ] result = 0;
) y3 W/ n# g' K. t+ H9 w7 }; R while(postfix!=' ')7 a2 ^# \6 k6 @% _" P- N
{
) R: ~2 d6 z. G5 u. h! Z- ?1 ~ result = result*10+postfix[i++]-'0';: v0 P( w" H( a0 j
}
% ^8 g# t( u4 B2 o- W i++;
* I9 C0 f" x" F' g5 P; B! _ stack.push(result);/ H2 W# {; b! x
}5 ~% }% l8 b1 g2 R9 B
else. }9 y$ e: [- X# Q& m- l
{
a' }# N" |& W if(postfix!=' ')6 F( }7 e. a6 X8 r) w
{
* ]# m6 @3 S' ` int y = stack.pop();( d H. G7 K& q
int x = stack.pop();- u/ o& ]& v6 p/ I- ?2 N' A
switch(postfix)2 H% P' X1 E( k3 H1 v, }
{- _" _' y1 @7 ^) v. O8 p
case'+':result = x + y;
, U1 E6 @; I ~* i( e0 a9 ? break;4 B1 ~ ^3 A3 V
case'-':result = x - y;, L% n% Y( {. N7 S1 ]9 L
break;
/ h5 x r2 g5 r* f- {6 n: U* n case'*':result = x *y;9 D4 j0 {5 `% G3 w8 B% z p. o
break;
3 @8 {5 U m- e$ D0 Q case'/':result = x / y;
& s: k( w% _8 k M- _3 \3 u# m break;, W" v* S" Q3 y% G4 ~
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stack.push(result);4 u0 a/ I4 z: ]' W3 `5 B/ H
}
! G7 S8 ]/ g$ p9 J' i T, e6 ~& b i++;
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1 @' N) R; X& c; z }
$ L: J; }5 j7 Y return stack.pop();
' r+ x& e2 \& Q0 Y" a}
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int main()6 y# v" O7 o# L' \6 Z
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//char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
% [7 X# ]9 h5 R) f cout << "请输入表达式:";2 L8 O1 E7 {: i( Q: f2 @ X3 i
//char *a ;
' X! E8 }# L; { //cin >> *a;
! U; M M- V+ [+ ?) [ char expstr[20]={0};
" b) S% K8 X4 N4 Z7 S# i: b while(1)
Z: K5 O( r6 w& X+ f {8 B1 m6 o8 g6 P3 g: _; w- K
cin>>expstr;
5 |8 p2 K; p% W2 E) q9 o* d' c char *postfix = toPostfix(expstr);
$ H: g& w7 W U- Z5 ?: P/ }# J cout << "expstr= "<<expstr << endl;$ M2 r8 m; G4 Y d
cout << "postfix= "<<postfix<<endl;
: L% r$ Z4 ^: {/ { cout << "value= "<<value(postfix) << endl;
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return 0;$ M* p! l: G3 T7 G0 F
} |