括号配对.cpp

输入一个式子

#include<iostream>
#include<cstring>
#include "assert.h"
#define NULL 0
using namespace std;
class stack
{
public:
	char *elmlist;
	char top;
	char msize;
	stack(int sz=20)
	{
		msize=sz;
		elmlist=new char[msize];
		assert(elmlist!=NULL);
		top=-1;
	}
	~stack()
	{delete []elmlist;}
	void push(char i);
	char pop();
	char gettop();
	void makeempty();
	int isfull(){return top==msize;}
	int isempty(){return top==-1;}

};

void stack::push(char i)
{
	assert(!isfull());
	top++;
	elmlist[top]=i;
}

char stack::pop()
{
	assert(!isempty());
		return elmlist[top--];
	
}
char stack::gettop()
{
	assert(!isempty());
	return elmlist[top];
}


void stack::makeempty()
{
	top=-1;
}


void match(char *s)
{
	stack a(10);
	int i=0;
	char k=s[i];
	
		while(k!='\0')
		{	 k=s[i];
		   if(k=='(')
		   {
			   a.push(k);i++;
		   }
		   else if(k== ')')
		   {
			   if(!a.isempty())
				  {
					  a.pop();
					  i++;
				  }
			      else 
				  {
					  cout<<"括号配对错误！"<<endl;
				       exit(0);
				  }
		   }
           else i++;
		}
	
		if(a.isempty())
			cout<<"括号配对成功！"<<endl;
		else
			cout<<"括号配对错误！"<<endl;
}


void main()
{
	char s[20];//={"5+8*(1-2)/3\0"};
	cout<<"请输入一个式子：";
cin.getline(s,20);
	match(s);
}