代入以下代码,得:11,9,4,2,1,6 滑稽~: v* \! H, i) e( W2 i
( z0 H5 Z4 Q2 a- I2 {4 J) f- z#include <iostream>8 X" q* `6 a% I2 ~! X0 _* |8 }& t
#include <string.h>/ F! t6 h1 S! G( H( h2 J0 }9 U. B- r
using namespace std;& ^1 P* k' U/ l, a% x
template <class T>
, k5 w y- q3 j( T5 I5 W, y: vclass Node
7 G+ n/ t4 B/ L% P{
+ ~1 @' P2 z8 mpublic:
. m* _, a: S; ? T data;! M; o7 L3 M4 P1 u* O1 `
Node<T> *next;) J% k, o$ t( r( m1 [5 ]+ Y" T
Node()
9 m" c( K0 s9 \3 B4 ~! W* t {
; |: K5 e# k) O( u, N3 e* M this->next = NULL;
8 l$ ~$ l/ t4 i1 Y. \( ? }
" O" a/ W) i& M' w' |* w& J Node(T data,Node<T> *next=NULL)
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this->data = data;4 d, T2 k6 T* D5 w9 f; Y2 X
this->next = next;: \+ @( x1 ~# Y$ U! O. n% c N4 h
}
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9 S9 F& z- P5 W5 D3 F1 Gtemplate <class T> ]% `- [$ L7 a2 M
class LinkedStack
0 C* p, L6 ]. J5 I1 H{
6 Y' K$ b) u* a4 X2 E6 dprivate:0 [( w, u, V/ A# R
Node<T> *top;. `7 e) j! m' C1 [- V
public:
, e3 Y3 Q. t c. k4 k LinkedStack();
& r h9 x. ^" J+ X ~LinkedStack();
, R9 s2 b# E. n0 n7 b: f bool isEmpty();& O" e2 u/ z7 X
void push(T x);
9 p i: Z' j5 \5 ^ T pop();
0 G' F9 D" S/ t# u& ?% V8 w3 p: | T get();
4 z6 c8 k' o4 ~};
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template <class T>
, q6 N0 i2 o; K5 B" eLinkedStack<T>::LinkedStack()! s4 r* |; H8 s
{( Y' m2 b+ m9 a- ~1 | H
top = NULL;1 t7 a4 P, t, h3 {0 ?
}
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template <class T>
( U' s" g" u y# M ?0 lLinkedStack<T>::~LinkedStack()! [) g* F( d! r
{
) C* o" Q3 g/ C' H/ u L. ?% l# G Node<T> *p = top;
7 O) R6 q7 d6 s+ ~) _2 Y" W Node<T> *q;; g7 D* z" I# \+ ^/ v8 H0 n! Z$ L& c
while(p!=top)8 A! _4 @# F7 t8 @) e3 K3 a: S- k! k
{- n' u0 Y6 \8 h, T! A
q = p;
7 v- s7 L% I8 R0 E2 s# c0 q- b( V p = p->next;/ @9 k. o' [- |
delete p;
1 p$ Q6 Y5 X' @9 b. L! |+ O: _% r }
) p2 |4 D/ J$ x. F* H top = NULL;$ U2 a; S& s7 c
}
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' W5 r3 d7 L5 R7 t m( w0 Ctemplate <class T>
( t( j- f9 U; S9 r t" H. Dbool LinkedStack<T>::isEmpty()1 t1 G$ P# V1 j: ^9 n1 O8 x
{
8 o0 `4 U$ n# n- K return top == NULL;; E& P5 b( K( @; ?( F
}
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2 B5 k7 w. Q" m$ O. }: ^template <class T>
# m }- s& N( ^0 l* mvoid LinkedStack<T>::push(T x)
! N1 x$ b7 @" |5 W* p{
& e5 Y" {& J# q8 O" |$ j' H( D9 N top = new Node<T>(x,top);
* g5 Q" m5 w. |4 u. }# t! @}
: l, M; X# S$ W' E2 t, q4 H0 ?# ^9 i* G' }
template <class T>8 G* ]! @. S+ h: J. y5 P
T LinkedStack<T>::pop(); ?& _4 w1 ?4 Y+ i6 ?
{1 ^$ U+ c& T9 K8 Y9 w5 k0 p
if(!isEmpty())' W0 f" d3 D, ?% C6 _% h Y8 `3 _
{/ U$ ]; s7 ~, d k' h" z7 |( N
T x = top->data;% I0 |. y; T# A. n
Node<T> *p = top;( s# X6 k, b5 O+ z7 a0 b$ D9 b4 g
top = top->next;% n8 B, A" U) x2 i, S) R
delete p;; [" k; U: D9 u! x. ]1 k
return x;6 o$ F" O2 i; H& `
}
& {+ L4 \9 p7 p5 E- I throw "空栈,不能执行出栈操作";: a( W& u& l. V' S- U) y, j9 O
}
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2 Q2 T* d: l& U W. {; Y! a; Q6 R8 |( F! ^template <class T> {* C5 c. {: a5 Y
T LinkedStack<T>::get()
9 U. P3 B2 K( {/ e0 P# z+ j3 F+ v{
* Z' Q3 a4 z6 S, K; ]9 ~+ L if(!isEmpty())
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return top->data;* e2 U1 U4 l& k% p& E) t
}+ N2 R8 L2 S* R5 q( M
throw "空栈,不能获得栈顶元素";) [0 U# ?# C9 z7 X7 L' ~+ Q
}8 g Y$ X3 }# e. z
/ |5 L+ |3 R9 b1 V: Y7 ochar * toPostfix(char *expstr)
* M+ \) g7 P7 a$ p5 K2 ?{
: T u3 D& A1 i LinkedStack<char> stack;9 C3 {# O; @( m; Z
char *postfix = new char[strlen(expstr)*2];2 c q# r0 y9 m4 C3 l6 S3 o, S
int i=0;
: o. d! T1 v. d. ?; o( K int j=0;* G% W, a: D5 H1 a* C, h: k- a
char out ;0 f8 S" \! [' T3 P2 e- x; Z
while(expstr[i]!='\0')
/ Q. l. `- U+ y6 Z {
8 J4 }% A. k/ G6 R4 z0 ~ switch(expstr[i])
5 A" ? [5 Z$ h6 g8 u {+ c5 ~9 j" R8 H% O& u) a
case'+':
9 k# X( i3 q+ R! b' V2 P case'-':
! Y3 u4 P6 O# T9 P3 V( y while(!stack.isEmpty()&&stack.get()!='(')% K# w* ]( C( @1 r: }( f! q* ?2 s
{# a5 X0 Z* O, A O
postfix[j++] = stack.pop();+ ^' O, i7 w+ n. P( j$ [' Q- y
}
! J6 F) T! o- D2 n stack.push(expstr[i++]);
# C7 |( e6 N3 `4 I break;2 o9 A+ S/ w: P' y5 Q5 X* Q8 V
case'*':0 L8 l5 M$ V }/ \
case'/':
. ^; L6 c1 l- I- E while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))8 R/ j) \$ B% E
{# x4 h8 l6 W* J1 U5 s( }% Y9 P
postfix[j++] = stack.pop(); j6 i6 b! G6 }
}
M8 Y2 S G, F! H5 E stack.push(expstr[i++]);+ d7 ?. }2 Z1 [' x* O
break;2 v; |. v5 [- g2 a& z- @: t
case'(':stack.push(expstr[i++]);6 k- c; b7 J5 H8 ^8 M" P' a
break;* ]4 `/ e$ b2 e9 f& ~
case')':out = stack.pop();
6 I6 r) B( s* ]- R6 x9 C while(!stack.isEmpty()&&out!='(')
& p1 u' |( U, ]3 [ {9 R# p2 m! g, l
postfix[j++] = out;
; C4 l7 p7 j4 I0 Q- G1 o4 v" C1 U$ v# X out = stack.pop();8 _3 N ^# B# P3 ~
}& f3 L; j' B [( U; v
i++;
q" D- d+ |. v0 x1 G break;- B' l; c. \" f, A' \
default:' W2 V7 W0 }8 g
while(expstr[i]>='0'&&expstr[i]<='9'&&expstr[i]!='\0')
* P$ C% }/ y" e& | {
8 k+ b0 c# P: u; O1 i postfix[j++] = expstr[i++];
/ H8 U& L) q2 ?; X J, R5 i; v }
! y; _- e! J4 V$ h postfix[j++]=' ';
* i. Y A1 n5 O break;' [9 w% `( {& w4 E A; Z& a
}) e! N4 t- A; t: \
}+ f" x4 |- s6 Z8 _5 y
while(!stack.isEmpty())8 o/ Y, T4 T( v. E9 B
{+ Z( z9 q& K- j' g2 k
postfix[j++]=stack.pop();+ I9 S6 K: F y D; }( F
}
3 y$ x7 d, @4 g3 ^ postfix[j]='\0';
' ? O1 ]5 k' l/ v P6 H, W/ _ return postfix;
|9 Z- B) l3 y9 m6 j { U: K}
# N. `) Z: U% u) B7 F0 D
: V" y' v& f5 G pint value(char *postfix)
3 X7 Y& Z1 k; H+ x{
$ ]& p3 V" j; f) t7 h LinkedStack<int> stack;) ?* M" Y% g- ?& T
int i=0;& {9 _/ D: c( B# l1 M% k. p4 i4 h- }
int result = 0;2 a; J# M x. |. `5 c6 U5 o! K
while(postfix[i]!='\0')
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if(postfix[i]>='0'&&postfix[i]<='9')
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result = 0;
* k& O" z4 n3 t while(postfix[i]!=' ')
7 k" g2 z) \- G* Y, W {
0 x* G8 k0 G" _' ` result = result*10+postfix[i++]-'0';1 S' c8 q7 @+ n! p$ n% X3 t8 ]
}5 A# g- o4 l4 ]
i++;* [5 ]$ D% I2 I) R4 a( w/ J
stack.push(result);6 f% |1 a; L3 Z( I' V
}) N. t7 G! _% s% \
else
& O2 W2 l2 n& Y {0 K- l, S# O8 t" j/ Y0 B4 ~8 A: @
if(postfix[i]!=' ')
' B4 k7 ]# q; M/ m; ^( o, [ {
1 a8 y5 Q7 @2 A& p$ B int y = stack.pop();
( v. y; b" R5 P6 f" j int x = stack.pop();
$ `6 J6 a! x3 P# c switch(postfix[i]) V5 [. ^$ T% T! n% `
{
% w, X. U6 s3 d- z! a' y case'+':result = x + y;
8 a/ p: u$ B# P* \: { break;
2 j6 G/ W" b+ T! Q case'-':result = x - y;9 ^: |$ k' W, Z1 p5 c
break;( P, i; X" I! ]- S! _7 N
case'*':result = x *y;' s7 y& B t5 p
break;, m- b+ \$ {+ b/ N6 `" d4 D* l% S
case'/':result = x / y;% L4 B+ }1 [; f r6 a N% L6 |9 h
break;
; L* w$ I$ U3 p+ Q+ e7 `3 U3 h }
0 P r! l3 j" o1 A6 @. O1 @( M7 L' g stack.push(result);1 k+ u: U- P* v+ e/ }. D
}
' @" p$ g$ |' x i++;
) J& ~6 O4 T6 N( U }3 n0 V2 k9 s& O" w1 u0 v& N6 A, c$ @
}
$ r7 g3 G' v) | J2 S return stack.pop();
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* e; x; [) v0 ]2 {$ {int main()1 B) [3 T5 l% |# {1 D$ |6 e
{* E& h' R: W8 Q' P: r0 p f
//char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";7 |# @3 o8 U; w) J
cout << "请输入表达式:";
* a0 d% |* T1 N //char *a ;4 D! e& z/ Y8 h) a2 x
//cin >> *a;
, X; ?+ e) [) \1 A! H3 y! } char expstr[20]={0};
* H5 h" K1 \, x% @. P while(1)- T3 B# n M! L( x0 B) a8 @9 ^
{
! B9 J* a3 R3 G0 }- _; s, Y. p cin>>expstr;
; u2 \* I3 {; J) `+ k, W char *postfix = toPostfix(expstr); m$ u/ G4 I0 B# f' g9 z0 u- a9 }
cout << "expstr= "<<expstr << endl;$ m5 H1 |5 `. J2 G% y! I
cout << "postfix= "<<postfix<<endl;
. J% h5 a3 h) r$ B# g. y cout << "value= "<<value(postfix) << endl;+ G& a+ V$ I0 N d9 X
}+ @/ j4 F+ ]5 C" Q9 @
return 0;
) p6 B$ e; N$ \! ~} |