数据结构实验2---表达式求值（“栈”实现）

#include<iostream>

#include<string>

#include <sstream>

#include<fstream>

#define STACK_INIT_SIZE 100

#define INCREAMENT 100

#define ZUIDAWEISHU 10

#define ERROR 0

using namespace std;

class YunSuanFu{//运算符类

char fuhao;

int pri;

public :

char get_fuhao(){

return fuhao;

}

int get_pri(){

return pri;

}

void set_fuhao(char e){

fuhao = e;

}

void set_pri(int e){

pri = e;

}

YunSuanFu(char e){

fuhao = e;

if(e == '(' || e == ')' || e == '#')

pri = 0;

if(e == '+' || e == '-')

pri = 1;

if(e == '*' || e == '/')

pri = 2;

}

YunSuanFu(){//函数体为空

}

};

typedef struct{//SqStack1

int * bottom;

int * top;

int stacksize;

}SqStack1;

typedef struct{//SqStack2

YunSuanFu * bottom;

YunSuanFu * top;

int stacksize;

}SqStack2;

bool createStack1(SqStack1 &s){//创建栈

int a[STACK_INIT_SIZE];

s.bottom = a;

if(!s.bottom){

return false;

}

s.stacksize = STACK_INIT_SIZE;

s.top = s.bottom;

return true;

}

bool createStack2(SqStack2 &s){//创建栈

YunSuanFu a[STACK_INIT_SIZE];

s.bottom = a;

if(!s.bottom){

return false;

}

s.stacksize = STACK_INIT_SIZE;

s.top = s.bottom;

return true;

}

bool isEmpty1(SqStack1 &s){//判空

return s.bottom == s.top ? true : false;

}

bool isEmpty2(SqStack2 &s){

return s.bottom == s.top ? true : false;

}

bool get_top1(SqStack1 &s1, int &e){//得到栈顶元素

if(s1.top == s1.bottom)

return false;

e = *(s1.top - 1);

return true;

}

bool get_top2(SqStack2 &s2, YunSuanFu &e){

if(s2.top == s2.bottom)

return false;

e.set_fuhao((*(s2.top - 1)).get_fuhao());

e.set_pri((*(s2.top - 1)).get_pri());

return true;

}

bool push1(SqStack1 &s, int &e){//入栈

if((s.top - s.bottom ) >= s.stacksize){

int *newbase =(int*) realloc (s.bottom,(s.stacksize + INCREAMENT) * sizeof(int));

if(!newbase)

return false;

s.bottom = newbase;

s.top = s.bottom + s.stacksize;

s.stacksize += INCREAMENT;

}

*(s.top) = e;

cout<<*(s.top)<<endl;//ceshi

cout<<s.top<<endl;//ceshi

++(s.top);

return true;

}

bool push2(SqStack2 &s, YunSuanFu &e){

if(s.top - s.bottom >= s.stacksize){

YunSuanFu* newbase =(YunSuanFu*) realloc (s.bottom,(s.stacksize + INCREAMENT) * (sizeof(char)+sizeof(int)));

if(!newbase)

return false;

s.bottom = newbase;

s.top = s.bottom + s.stacksize;

s.stacksize += INCREAMENT;

}

(s.top)->set_fuhao(e.get_fuhao());//类不能直接赋值！！！

(s.top)->set_pri(e.get_pri());

s.top++;

return true;

}

bool pop1(SqStack1 &s, int &e){//出栈

if(s.top == s.bottom)

return false;

e = *(s.top - 1);//这里有错误

cout<< e<<endl;//ceshi

cout<<s.top-1<<endl;//ceshi

--s.top;

return true;

}

bool pop2(SqStack2 &s, YunSuanFu & e){

if(s.top == s.bottom)

return false;

e.set_fuhao((*(s.top - 1)).get_fuhao());

e.set_pri((*(s.top - 1)).get_pri());

s.top--;

return true;

}

void jisuan(SqStack1 &s1,SqStack2 & s2){//计算

int e1,e2;

YunSuanFu e3;

pop2(s2,e3);

if(e3.get_fuhao() == '+'){

pop1(s1,e1);

pop1(s1,e2);

int jieguo = e2 + e1;

push1(s1,jieguo);

}

if(e3.get_fuhao() == '-'){

int e1,e2;

pop1(s1,e1);

pop1(s1,e2);

int jieguo = e2 - e1;

push1(s1,jieguo);

}

if(e3.get_fuhao() == '*'){

int e1,e2;

pop1(s1,e1);

pop1(s1,e2);

int jieguo = e2 * e1;

push1(s1,jieguo);

}

if(e3.get_fuhao() == '/'){

int e1,e2;

pop1(s1,e1);

pop1(s1,e2);

int jieguo = e2 / e1;

push1(s1,jieguo);

}

}

//还要定义一个合法性检验函数

void ceshi(){//测试函数

cout<<"进来了"<<endl;

}//ceshi();//测试

void biaodashiqiuzhi(string lujing){//表达式求值

string wenjianlujing = lujing;

SqStack1 s1;

SqStack2 s2;

createStack1(s1);

createStack2(s2);

ifstream in;

in.open(wenjianlujing,ios::out);

char t[ZUIDAWEISHU];

in>>t;

static string shuzhizichuan = "";//后面用

for(int i = 0,count1 = 0; t[i] != '\0'; i++){

if(t[i] == '+' || t[i] == '-' || t[i] == '*' || t[i] == '/' || t[i] == '('|| t[i] == ')' || t[i] == '#'){

if(t[i] == '#'){//测试ok

if(count1 == 0){

YunSuanFu yunsuanfu = YunSuanFu(t[i]);

push2(s2,yunsuanfu);

count1 = 1;

}else{

YunSuanFu yunsuanfu1;

do{

jisuan(s1,s2);

get_top2(s2,yunsuanfu1);

}while(yunsuanfu1.get_fuhao() != '#');

int e1;

pop1(s1,e1);

YunSuanFu e;

pop2(s2,e);

if(isEmpty2(s2) && isEmpty1(s1)){

cout<<"jieguoshi:"<<e1<<endl;

}else{

return ERROR;

}

count1 = 0;

}

}

if(t[i] == '('){

YunSuanFu yunsuanfu = YunSuanFu(t[i]);

push2(s2,yunsuanfu);

}

if(t[i] == ')'){

YunSuanFu yunsuanfu1;

do{

jisuan(s1,s2);

get_top2(s2,yunsuanfu1);

}while(yunsuanfu1.get_fuhao() != '(');

YunSuanFu e;

pop2(s2,e);

}

if(t[i] == '+' || t[i] == '-' || t[i] == '*' || t[i] == '/'){

YunSuanFu yunsuanfu = YunSuanFu(t[i]),yunsuanfu2;

get_top2(s2,yunsuanfu2);

if(yunsuanfu.get_pri() > yunsuanfu2.get_pri()){

push2(s2,yunsuanfu);

}else{

YunSuanFu yunsuanfu1;

do{

jisuan(s1,s2);

get_top2(s2,yunsuanfu1);

}while(yunsuanfu.get_pri() <= yunsuanfu1.get_pri());

push2(s2,yunsuanfu);

}

}

}else{

shuzhizichuan = shuzhizichuan + t[i];

if(!(t[i + 1] == '+' || t[i + 1] == '-' || t[i + 1] == '*' || t[i + 1] == '/' || t[i + 1] == '('|| t[i + 1] == ')' || t[i + 1] == '#')){

continue;

}else{

int shuzhi;

stringstream ss;

ss<<shuzhizichuan;

ss>>shuzhi;

push1(s1, shuzhi);

shuzhizichuan = "";

}

}

}

in.close();

}

int main(){//主函数

// SqStack1 s1;//测试用

//SqStack2 s2;

//createStack1(s1);

//createStack2(s2);

//int e1 = 3;

//bool t2 = push1(s1,e1);

//cout<<"s1.top: "<<*(s1.top - 1)<<endl;

//cout<<t2<<endl;

//bool t1 = isEmpty1(s1);

//cout<<t1<<endl;

//int e = 0;

//bool t3 = pop1(s1,e);

//bool t4 = isEmpty1(s1);

//cout<<t3<<endl<<e<<endl;

string lujing = "biaodashi.txt";

biaodashiqiuzhi(lujing);

}