#include

#include

#include

#include

char prog[80]; //存放所有输入字符

char token[8]; //存放词组

char ch; //单个字符

int syn,p,m,n;//syn:种别编码

double sum;

int count;

int Signal;         //是否带正负号(0不带，1负号)

int xiaoshu;      //是否是小数

double isxiaoshu;       //小数

int zhishu;           //是否是指数

int index;            //指数幂

int fushu;       //是否带负号

double temp;

int temp2;

void scanner();

char *rwtab[6]={“function”,”if”,”then”,”while”,”do”,”endfunc”};

int main()

{

p=0;

count=0;

xiaoshu=0;

index=0;

int b,a;

FILE *fp;

printf(“以文件输入请按1！\n”);

printf(“以键盘输入请按2！\n”);

scanf(“%d”,&a);

if(a==1)

{

if((fp=fopen(“D:\111.txt”,”r”))==NULL)

{

printf(“Failure to open 111.txt!\n”);

exit(0);

}

fscanf(fp,”%s”,prog);

fclose(fp);

}

else if(a==2)

{

printf(“\n Please input string:\n”);

do{

ch=getchar();

prog[p++]=ch;

}while(ch!=””#””);

}

p=0;

do{

scanner();

switch(syn)

{

printf(“以文件输出请按1！\n”);

printf(“以屏幕输出请按2！\n”);

scanf(“%d”,&b);

if(b==1)

{

case 11:  if(xiaoshu==0)

{

fprintf(fp,”%2d,%8d”,syn,(int)sum);

//printf(“(%2d,%8d)\n”,syn,(int)sum);

break;

}

else if(zhishu==1)

{

fprintf(fp,”(%2d,%10.5e)\n”,syn,sum);

//printf(“(%2d,%10.5e)\n”,syn,sum);

zhishu=0;

xiaoshu=0;

break;

}

else if(xiaoshu==1)

{

fprintf(fp,”(%2d,%8.4f)\n”,syn,sum);

//printf(“(%2d,%8.4f)\n”,syn,sum);

xiaoshu=0;

break;

}

case -1:

fprintf(fp,”input error\n”);

printf(“input error\n”);

break;

default:

fprintf(fp,”(%2d,%8s)\n”,syn,token);

//printf(“(%2d,%8s)\n”,syn,token);

}

}while(syn!=0);

return 0;

}

else if(b==2)

{

case 11:  if(xiaoshu==0)

{

printf(“(%2d,%8d)\n”,syn,(int)sum);

break;

}

else if(zhishu==1)

{

printf(“(%2d,%10.4e)\n”,syn,sum);

zhishu=0;

xiaoshu=0;

break;

}

else if(xiaoshu==1)

{

printf(“(%2d,%8.4f)\n”,syn,sum);

xiaoshu=0;

break;

}

case -1:

printf(“input error\n”);

break;

default:

printf(“(%2d,%8s)\n”,syn,token);

}

while(syn!=0);

return 0;

}

void scanner()

{

sum=0;

isxiaoshu=0;

m=0;

for(n=0;n<8;n++)

token[n]=NULL;

ch=prog[p++];

while(ch==”” “”||ch==””\n””||ch==””\t””)

ch=prog[p++];

if(((ch>=””a””)&&(ch<=””z””))||((ch>=””A””)&&(ch<=””Z””)))

{

while(((ch>=””a””)&&(ch<=””z””))||((ch>=””A””)&&(ch<=””Z””))||((ch>=””0″”)&&(ch<=””9″”)))

{

token[m++]=ch;

ch=prog[p++];

}

token[m++]=””\0″”;

p–;

syn=10;

for(n=0;n<6;n++)

if(strcmp(token,rwtab[n])==0)

{

syn=n+1;

break;

}

}

else

if((ch>=””0″”)&&(ch<=””9″”))

{

Num:

if(Signal==1)

{

token[m++]=””-“”;

}

while((ch>=””0″”)&&(ch<=””9″”))

{

sum=sum*10+ch-“”0″”;

ch=prog[p++];

}

if(ch==””.””)

{

xiaoshu=1;

ch=prog[p++];

while((ch>=””0″”)&&(ch<=””9″”))

{                                  //pow(x,y)计算x的y次幂

temp=(ch-“”0″”)*pow(0.1,++count);

isxiaoshu=isxiaoshu+temp;

ch=prog[p++];

}

sum=sum+isxiaoshu;

}

if(ch==””e””||ch==””E””)

{

zhishu=1;

ch=prog[p++];

if(ch==””-“”)

{

fushu=1;

ch=prog[p++];

}

while((ch>=””0″”)&&(ch<=””9″”))

{                               //指数

index=index*10+ch-“”0″”;

ch=prog[p++];

}

if(fushu)

sum=sum*pow(0.1,index);

else

sum=sum*pow(10,index);

}

if(Signal==1)

{

sum=-sum;

Signal=0;

}

p–;

syn=11;

}

else

switch(ch)

{

case “”

m=0;

token[m++]=ch;

ch=prog[p++];

if(ch==””=””)

{

syn=21;

token[m++]=ch;

}

else if(ch==””=””)

{

syn=21;

token[m++]=ch;

}

else

{

syn=20;

p–;

}

break;

case “”>””:

m=0;

token[m++]=ch;

ch=prog[p++];

if(ch==””=””)

{

syn=24;

token[m++]=ch;

}

else

{

syn=23;

p–;

}

break;

case “”=””:

m=0;

token[m++]=ch;

ch=prog[p++];

if(ch==””=””)

{

syn=25;

token[m++]=ch;

}

else

{

syn=18;

p–;

}

break;

case “”+””:

temp2=prog[p];

if((temp2>=””0″”)&&(temp2<=””9″”))

{

Signal=2;

ch=prog[p++];

goto Num;

}

syn=13;

token[m++]=ch;

break;

case “”-“”:

temp2=prog[p];

if((temp2>=””0″”)&&(temp2<=””9″”))

{

Signal=1;

ch=prog[p++];

goto Num;

}

syn=14;

token[m++]=ch;

break;

case “”*””:

syn=15;

token[m++]=ch;

break;

case “”/””:

syn=16;

token[m++]=ch;

break;

case “”;””:

syn=26;

token[m++]=ch;

break;

case “”(“”:

syn=27;

token[m++]=ch;

break;

case “”)””:

syn=28;

token[m++]=ch;

break;

case””#””:

syn=0;

token[m++]=ch;

break;

default:

syn=-1;

}

}