#include<iostream>
#include<stdio.h>
#include<string.h>
#include<iomanip>
using namespace std;
//創(chuàng)建四個(gè)表,儲(chǔ)存符號(hào) 
const char *k[13]={"begin","call","const","do","end","if","odd","procedure","read","then","var","while","write"};//關(guān)鍵字表
const char *s1[5]={",",".",";","(",")"};//界符表
const char *s2[6]={"+","-","*","/","++","--",};//運(yùn)算符號(hào)表 
const char *s3[9]={"<=",">",">=","=",">",">=","<>",":=","#"}; //關(guān)系運(yùn)算符號(hào)表 
//定義全局變量
int row=1,line=1; 
int t,p=0;//單詞類別碼以及記錄移動(dòng)指針
char instring[100];//保存輸入的程序代碼緩存數(shù)組
char outtoken[10];//輸出
char ci[8],id[10];//暫時(shí)保存數(shù)字和字符
//函數(shù)的聲明
void analysis();//分析函數(shù)，決定調(diào)用哪個(gè)函數(shù)進(jìn)行分析
void symbol();//分析以非字母數(shù)字開頭的字符
void constant();//分析常數(shù)
void alphabet();//分析標(biāo)識(shí)符和關(guān)鍵字
void show();//打印輸出函數(shù)
bool isnumber(char x);//判斷是否是數(shù)字 
bool isalpha(char x);//判斷是否是字母 
int main(){
	cout<<"請(qǐng)輸入一段程序代碼并以@結(jié)束:"<<endl;
	//輸出程序代碼 
	do{
		instring[p++]=getchar();
	} while(instring[p-1]!='@'); 
	getchar();//吸收回車鍵 
	instring[p-1]='\0';//抵消掉@
	p=0;//移動(dòng)指針歸零
	cout<<left;
	cout<<"------------------------------------------------------------------------------"<<endl; 
	cout<<setw(6)<<"單詞"<<"			"<<setw(6)<<"二元序列"<<"			"<<setw(6)<<"類型"<<"			"<<endl;
	//掃描輸入的字符 
	while(p<strlen(instring)){
		analysis();
		show();
	} 
	cout<<"------------------------------------------------------------------------------"<<endl; 
	cout<<"[注]:"<<endl;
	cout<<"t=1:關(guān)鍵字,"<<"t=2:分界符，"<<"t=3:算術(shù)運(yùn)算符，"<<"t=4:關(guān)系運(yùn)算符，"<<"t=5:常數(shù)，"<<"t=6：標(biāo)識(shí)符，"<<"t==7:詞法出錯(cuò)"<<endl; 
	cout<<"@為結(jié)束符，不參與到詞法分析中"<<endl; 
	cout<<endl;
	return 0;
} 
//判斷是否是數(shù)字
bool isnumber(char x){
	return x>='0'&&x<='9';
}
//判斷是否是字母
bool isalpha(char x){
	return (x>='a'&&x<='z'||x>='A'&&x<='Z');
}
//分析函數(shù)，決定調(diào)用哪個(gè)函數(shù)進(jìn)行分析
void analysis(){
	strcpy(outtoken,"");//清空outtoken數(shù)組
	while(instring[p]==' '||instring[p]=='\n'){
		if(instring[p]=='\n'){
			row++;
			line=1;
		}
		p++;
	} 
	//執(zhí)行完之后指向第一個(gè)不為空格的字符
	char ch=instring[p];
	//按照字符的類別調(diào)用不同的分析處理函數(shù) 
	if(isalpha(ch))
	   alphabet();
	else if(isnumber(ch))
		constant();
	else 
		symbol();
}
//常數(shù)處理函數(shù)
void constant(){
	strcpy(ci,"");//清空ci
	t=5;//類別碼
	int i=0;
	while(isnumber(instring[p])){
		ci[i++]=instring[p++]; 
	} 
	while(isalpha(instring[p])||isnumber(instring[p])){
		ci[i++]=instring[p++];
		t=7;//出錯(cuò) 
	}
	ci[i]='\0';//結(jié)束符
	//strcpy_s(outtoken,strlen(ci)+1,ci);
	strcpy(outtoken,ci);
	line++;
	return; 
} 
//標(biāo)識(shí)符和關(guān)鍵字的分析函數(shù)
void  alphabet(){
	strcpy(id,"");//清空id
	int i=0;
	//讀取連續(xù)的字母數(shù)字序列 
	while(isalpha(instring[p])||isnumber(instring[p])){
		id[i++]=instring[p++];//p指向連續(xù)序列之后的第一個(gè)字符 
	} 
	id[i]='\0';
	//查關(guān)鍵字表 
	for(i=0;i<8;i++){
		if(strcmp(id,k[i])==0){
			t=1;//表示關(guān)鍵字
			line++;
			strcpy(outtoken,id);
			return; //是關(guān)鍵字的話，直接退出 
		}
	}
	//查看是否是標(biāo)識(shí)符
	for(i=0;i<strlen(id);i++){
		if(!(isalpha(id[i])||isnumber(id[i]))){
			t=7;
			strcpy(outtoken,id);
			line++;
			return;
		}
	} 
	line++;
	t=6;//不是關(guān)鍵字且沒有出錯(cuò)即為標(biāo)識(shí)符
	strcpy(outtoken,id);
}
//其它運(yùn)算符的分析函數(shù)
void symbol(){
	char ch=instring[p++];
	char ch2=instring[p];
	t=7;
	switch(ch){
		case '+':
			if(ch2=='+')
			  t=3;
			break;
		case '-':
			if(ch2=='-')
			  t=3;
			break;
		case '>':
			if(ch2=='=')
			  t=4;
			break;
		case '<':
			if(ch2=='='||ch2=='>')
			  t=4;
			break;
		case ':':
			if(ch2=='=')
			  t=3;
			break;
	}
	//判斷是否具有兩個(gè)符號(hào)的運(yùn)算符
	if(ch=='>'&&ch2=='='||ch=='<'&&ch2=='='||ch=='<'&&ch2=='>'||ch=='+'&&ch2=='+'||ch=='-'&&ch2=='-'||ch==':'&&ch2=='='){
		p++;
		outtoken[0]=ch;
		outtoken[1]=ch2;
		outtoken[2]='\0';
		line++;
		return;
	} else{
		char chq[2];
		chq[0]=ch;
		chq[1]='\0';
		//分界符比較 
		for(int i=0;i<6;i++){
			if(strcmp(chq,s1[i])==0){
				t=2;
				break;
			}
		}	
		//算術(shù)運(yùn)算符比較 
		for(int i=0;i<6;i++){
			if(strcmp(chq,s2[i])==0){
				t=3;
				break;
			}
		}	
		//關(guān)系運(yùn)算符比較 
		for(int i=0;i<9;i++){
			if(strcmp(chq,s3[i])==0){
				t=4;
				break;
			}
		}
	}
	line++;
	outtoken[0]=ch;
	outtoken[1]='\0';
	return;
} 
//輸出函數(shù),根據(jù)以上分析函數(shù)進(jìn)行打印輸出分析的結(jié)果
void show(){
	cout<<left;
	//setw(6)表示占位寬度為6個(gè)字符 
	if(t==7){
		cout<<setw(6)<<outtoken<<"			"<<setw(6)<<"ERROR!"<<setw(11)<<" "<<setw(10)<<"ERROR!";
	}else{
		cout<<left;
		cout<<setw(6)<<outtoken<<"			"<<"<"<<t<<","<<outtoken;
		cout<<setw(6-strlen(outtoken))<<">"<<"			";
		switch(t){
			case 1:cout<<left<<setw(10)<<"關(guān)鍵字";break;
			case 2:cout<<left<<setw(10)<<"分界符";break;
			case 3:cout<<left<<setw(10)<<"算術(shù)運(yùn)算符";break;
			case 4:cout<<left<<setw(10)<<"關(guān)系運(yùn)算符";break;
			case 5:cout<<left<<setw(10)<<"常數(shù)";break;
			case 6:cout<<left<<setw(10)<<"標(biāo)識(shí)符";break;
		}
	} 
	cout<<endl;
} 
/*變量說明： 
k數(shù)組：關(guān)鍵字表; s數(shù)組：分界符表,其中分界符，算術(shù)運(yùn)算符，關(guān)系運(yùn)算符分別存放在s1,s2,s3數(shù)組中 
id:標(biāo)識(shí)符; ci：常數(shù) ；row:行 line:列，單詞的位置 
instring數(shù)組：為輸入源程序代碼的單詞緩存; outtoken數(shù)組：記錄為輸出內(nèi)部表示緩存
 symbol:分析//后的注釋;constant:常數(shù)分析;alphabet:標(biāo)識(shí)符和關(guān)鍵字分析
analysis:分析函數(shù)，根據(jù)輸入字符判斷調(diào)用哪一個(gè)函數(shù) ;show:輸出打印函數(shù)
t:單詞的種類 t=1:關(guān)鍵字 t=2:分界符 t=3:算術(shù)運(yùn)算符 t=4:關(guān)系運(yùn)算符 t=5:常數(shù) t=6：標(biāo)識(shí)符 t=7：出錯(cuò)*/