#ifndef PARSER_H
#define PARSER_H
#include <stack>
#include <string>
#include <map>
#include<algorithm>
#define NNUM 5
#define TNUM 8
using namespace std;
/*
 *
 *E->TG
 *G->-TG | +TG
 *G->epsilon
 *T->FM
 *M->*FM | /FM
 *M->epsilon
 *F->(E) | i
 *
 *
 *               语法分析表
 *       FIRST           FOLLOW
 *E      （,i            #,)
 *
 *G      +,-,epsilon     #,)
 *
 *T      (,i             +,-,#,)
 *
 *M      *,/,epsilon     +,-,#,)
 *
 *F      (,i             *,/,+,-,#,)
 *
 *LL(1) 分析表
 *
 *       (           )           i           +           -           *           /           #
 *E    E->TG                    E->TG
 *
 *G               G->epsilon               G->+TG      G->-TG                            G->epsilon
 *
 *T    T->FM                    T->FM
 *
 *M              M->epsilon              M->epsilon    M->epsilon   M->*FM     M->/EM    M->epsilon
 *
 *F    F->(E)                   F->i
 *
 * 
 * 
 * 步骤 	分析栈 	剩余输入串 	所用产生式 
 */

char token;
char VN[] = {'E', 'G', 'T', 'M', 'F'};
char VT[] = {'(', ')', 'i', '+', '-', '*', '/', '#'};
bool isVT(char);
bool isVN(char);
stack<char> analyseStack;
map<char, map<char, string>> selectMap;
void init();
string stackString();
bool existProduction(char VN,char VT);
bool isVN(char c)
{
    for (int i = 0; i < NNUM; i++)
    {
        if (c == VN[i])
            return true;
    }
    return false;
}
bool isVT(char c)
{
    for (int i = 0; i < TNUM; i++)
    {
        if (c == VT[i])
            return true;
    }
    return false;
}
void init()
{
    selectMap['E']['('] = "TG";
    selectMap['E']['i'] = "TG";
    selectMap['G'][')'] = "~";
    selectMap['G']['+'] = "+TG";
    selectMap['G']['-'] = "-TG";
    selectMap['G']['#'] = "~";
    selectMap['T']['('] = "FM";
    selectMap['T']['i'] = "FM";
    selectMap['M'][')'] = "~";
    selectMap['M']['+'] = "~";
    selectMap['M']['-'] = "~";
    selectMap['M']['*'] = "*FM";
    selectMap['M']['/'] = "/EM";
    selectMap['M']['#'] = "~";
    selectMap['F']['('] = "(E)";
    selectMap['F']['i'] = "i";

    analyseStack.push('#');
    analyseStack.push('E'); 
}
string stackString()
{
    char c;
    stack<char> temp;
    string s;
    while(!analyseStack.empty())
    {
        s.push_back(analyseStack.top());
        //s.append(to_string(analyseStack.top()));
        temp.push(analyseStack.top());
        analyseStack.pop();
    }
    while(!temp.empty())
    {
        analyseStack.push(temp.top());
        temp.pop();
    }
    reverse(s.begin(),s.end());
    return s;
}
bool existProduction(char VN,char VT) 
{
    auto it = selectMap.find(VN);
    if(it!=selectMap.end())
    {
        if(it->second.find(VT)!=it->second.end())
            return true;
    } 
    return false;   
}

#endif