#include <stdio.h>  #include <string.h>    char prog[80],token[8],ch;  int syn,p,m,n,sum;  char *rwtab[6]={"begin","if","then","while","do","end"};     void scaner(void);    main()  {      p=0;      printf("\n please input a string(end with ‘#‘):\n");            do{              scanf("%c",&ch);              prog[p++]=ch;      }while(ch!=‘#‘);            p=0;      do{              scaner();              switch(syn)              {                  case 11:                      printf("( %-10d%5d )\n",sum,syn);                  break;                                    case -1:                      printf("you have input a wrong string\n");                      //getch();                      return 0;                  break;                                    default:                   printf("( %-10s%5d )\n",token,syn);                  break;              }          }while(syn!=0);      //getch();   }    void scaner(void)  {        sum=0;            for(m=0;m<8;m++)          token[m++]= NULL;                ch=prog[p++];          m=0;                while((ch==‘ ‘)||(ch==‘\n‘))          ch=prog[p++];            if(((ch<=‘z‘)&&(ch>=‘a‘))||((ch<=‘Z‘)&&(ch>=‘A‘)))       {           while(((ch<=‘z‘)&&(ch>=‘a‘))||((ch<=‘Z‘)&&(ch>=‘A‘))||((ch>=‘0‘)&&(ch<=‘9‘)))          {              token[m++]=ch;              ch=prog[p++];          }                    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‘))       {           while((ch>=‘0‘)&&(ch<=‘9‘))          {              sum=sum*10+ch-‘0‘;              ch=prog[p++];          }          p--;          syn=11;      }      else       {          switch(ch)          {          case ‘<‘:              token[m++]=ch;              ch=prog[p++];              if(ch==‘=‘)              {                   syn=22;                  token[m++]=ch;              }              else              {                    syn=20;                  p--;              }          break;            case ‘>‘:              token[m++]=ch;              ch=prog[p++];              if(ch==‘=‘)              {                  syn=24;                  token[m++]=ch;              }              else              {                   syn=23;                  p--;              }          break;            case ‘+‘:              token[m++]=ch;              ch=prog[p++];              if(ch==‘+‘)              {                  syn=17;                  token[m++]=ch;              }              else              {                  syn=13;                  p--;              }          break;            case ‘-‘:              token[m++]=ch;              ch=prog[p++];              if(ch==‘-‘)              {                  syn=29;                  token[m++]=ch;              }              else              {                   syn=14;                  p--;              }          break;            case ‘!‘:              ch=prog[p++];              if(ch==‘=‘)              {                   syn=21;                  token[m++]=ch;              }              else              {                   syn=31;                  p--;              }          break;            case ‘=‘:              token[m++]=ch;              ch=prog[p++];              if(ch==‘=‘)              {                  syn=25;                  token[m++]=ch;              }              else              {                  syn=18;                  p--;              }          break;            case ‘*‘:              syn=15;              token[m++]=ch;          break;            case ‘/‘:              syn=16;              token[m++]=ch;          break;            case ‘(‘:               syn=27;              token[m++]=ch;          break;            case ‘)‘:              syn=28;              token[m++]=ch;          break;            case ‘{‘:               syn=5;              token[m++]=ch;          break;            case ‘}‘:               syn=6;              token[m++]=ch;          break;            case ‘;‘:              syn=26;              token[m++]=ch;          break;            case ‘\"‘:              syn=30;              token[m++]=ch;          break;            case ‘#‘:               syn=0;              token[m++]=ch;          break;            case ‘:‘:              syn=17;              token[m++]=ch;          break;            default:              syn=-1;          break;          }      }          token[m++]=‘\0‘;  }