编程实现英文数字到中文大写数字的转换

本程序实现英文数字到中文大写数字的转换。
主要思想是利用该语法自底向上地构造出1——>999999999999；
然后将数字转换成中文大写。
利用flex进行词法分析，bison进行句法分析。


语法如下：
e1-->one|two|three|four|five|six|seven|eight|nine
e2-->ten|eleven|twelve|thirteen|fourteen|fifteen|sixteen|seventeen|eighteen|nineteen
e3-->twenty|thirty|forty|fifty|sixty|seventy|eighty|ninety
 
e4-->e3-e1
    |e3
    |e2
    |e1
 
e51-->e1 hundred and e4
     |e1 hundred
e52-->e51
     |e4
 
e61-->e52 thousand e51
     |e52 thousand and e4
     |e52 thousand  
e62-->e61
     |e52
 
e71-->e52 million e61
     |e52 million e51
     |e52 million and e4
     |e52 million
e72-->e71
     |e62
 
e81-->e52 billion e71
     |e52 billion e61
     |e52 billion e51
     |e52 billion and e4
     |e52 billion
e82-->e81
     |e72
     |zero

lex.l文件如下:

%%zero     {yylval=0;return ZERO;}one      {yylval=1;return NUM1;}two      {yylval=2;return NUM1;}three    {yylval=3;return NUM1;}four     {yylval=4;return NUM1;}five     {yylval=5;return NUM1;}six      {yylval=6;return NUM1;}seven    {yylval=7;return NUM1;}eight    {yylval=8;return NUM1;}nine     {yylval=9;return NUM1;}ten     {yylval=10;return NUM2;}eleven  {yylval=11;return NUM2;}twelve  {yylval=12;return NUM2;}thirteen {yylval=13;return NUM2;}fourteen {yylval=14;return NUM2;}fifteen {yylval=15;return NUM2;}sixteen {yylval=16;return NUM2;}seventeen {yylval=17;return NUM2;}eighteen {yylval=18;return NUM2;}nineteen {yylval=19;return NUM2;}twenty   {yylval=20;return NUM3;}thirty   {yylval=30;return NUM3;}forty    {yylval=40;return NUM3;}fifty    {yylval=50;return NUM3;}sixty    {yylval=60;return NUM3;}seventy  {yylval=70;return NUM3;}eighty   {yylval=80;return NUM3;}ninety   {yylval=90;return NUM3;}hundred  {return HUNDRED;}thousand {return THOUSAND;}million  {return MILLION;}billion  {return BILLION;}and      {return AND;}[ \t]+   /* skip blanks */.|\n     { return yytext[0];}

parser.y文件如下：

%{#include<cmath>#include <string>#include <iostream>using namespace std;void yyerror(string msg);string trans(int term);void dtos(long term,string &result);int yylex();#define YYSTYPE long%}%token NUM1%token NUM2%token NUM3%token ZERO%token HUNDRED%token THOUSAND%token MILLION%token BILLION%token AND%%lines : lines e82 '\n' {string result;dtos($2,result);cout<<result<<endl;}      | lines '\n'      | /*empty*/      |error '\n' {yyerrok;}      ;e82:e81  {$$=$1;}   |e72  {$$=$1;}   |ZERO {$$=0;}   ;e81:e52 BILLION e71    {$$=$1*pow(10,9)+$3;}   |e52 BILLION e61    {$$=$1*pow(10,9)+$3;}   |e52 BILLION e51    {$$=$1*pow(10,9)+$3;}   |e52 BILLION AND e4 {$$=$1*pow(10,9)+$4;}   |e52 BILLION        {$$=$1*pow(10,9);}   ;e72:e71 {$$=$1;}   |e62 {$$=$1;}   ;e71:e52 MILLION e61    {$$=$1*pow(10,6)+$3;}   |e52 MILLION e51    {$$=$1*pow(10,6)+$3;}   |e52 MILLION AND e4 {$$=$1*pow(10,6)+$4;}   |e52 MILLION        {$$=$1*pow(10,6);}   ;e62:e61 {$$=$1;}   |e52 {$$=$1;}   ;e61:e52 THOUSAND e51 {$$=$1*pow(10,3)+$3;}   |e52 THOUSAND AND e4 {$$=$1*pow(10,3)+$4;}   |e52 THOUSAND {$$=$1*pow(10,3);}   ;e52:e51 {$$=$1;}   |e4 {$$=$1;}   ;e51:e1 HUNDRED AND e4 {$$=$1*pow(10,2)+$4;}   |e1 HUNDRED {$$=$1*pow(10,2);}   ;e4:e3'-'e1{$$=$1+$3;}  |e3 {$$=$1;}  |e2 {$$=$1;}  |e1 {$$=$1;}  ;e3:NUM3 {$$=$1;}  ;e2:NUM2 {$$=$1;}  ;e1:NUM1 {$$=$1;}  ;%%#include "lex.yy.c"int main() {    return yyparse();}void yyerror(string msg) {    cout<<msg<<endl;}string trans(int term){ if(term==1) return "壹"; if(term==2) return "贰"; if(term==3) return "叁"; if(term==4) return "肆"; if(term==5) return "伍"; if(term==6) return "陆"; if(term==7) return "柒"; if(term==8) return "捌"; if(term==9) return "玖";}void dtos(long term,string &result){ bool flag1=false,flag2=false,flag3=false,flag4=false; long temp1=term/100000000; if(temp1!=0) {  flag1=true;  dtos(temp1,result);  result+="亿"; } term%=100000000; long temp2=term/10000; if(temp2!=0) {  if(temp2<1000)  {   if(flag1)    result+="零";  }  flag2=true;  dtos(temp2,result);  result+="万"; }  else if(flag1) { result+="零";} term%=10000; long temp3=term/1000; if(temp3!=0) {  flag3=true;  result+=trans(temp3);  result+="仟"; } else if(flag2) {result+="零";} term%=1000; long temp4=term/100; if(temp4!=0) {  flag4=true;  result+=trans(temp4);  result+="佰"; }  else if(flag3) {result+="零";} term%=100; long temp5=term/10;  if(temp5!=0) {  result+=trans(temp5);  result+="拾"; } else if(flag4) {result+="零";} term%=10; long temp6=term; if(temp6!=0) result+=trans(temp6); if(result=="") result+="零"; string temp=result.substr(result.length()-3,result.length()); if((result!="零")&&(temp=="零")) {   result=result.substr(0,result.length()-3); }}

程序的运行：
flex lex.l
bison parser.y
g++ parser.tab.c -ly -ll
./a.out
输入英文数字回车得到对应的中文大写。