ass8.cpp

来自「lex files for given decription used as 」· C++ 代码 · 共 62 行

//IIT2006021
//Arunanshu Pandey
#include<iostream>
using namespace std;
void A();
void L();
void S();
void match(char);
char *ch="(a,a))";
char lookahead,nexttoken;
int i=0;

void match(char s)
{
       if(lookahead==s)
       {
               i++;
               nexttoken=ch[i];
               lookahead=nexttoken;
       }
       else
               cout<<"Error"<<endl;
}

void S()
{
       if(lookahead=='(')
       {
               match('(');
               L();
               match(')');
       }
       else if(lookahead=='a')
               match('a');
       else
               cout<<"Error";
}
void L()
{
       S();
       A();
}
void A()
{
       if(lookahead==',')
       {
               match(',');
               S();
               A();
       }
}

int main()
{
       lookahead=ch[i];
       S();
       return 0;
}