C-Language parsing parser

#include <stdio.h>#include<string.h>Charprog[ -], token[ -];Charch;intsyn,p,m,n,sum;Char* rwtab[6]= {"begin","if"," Then"," while"," Do","End"};main () {p=0; printf ("\ n Please enter a string: \ n");  Do{ch=GetChar (); Prog[p++]=ch; } while(ch!='#'); P=0;  Do{Scaner (); Switch(SYN) { Case  One: printf ("\ n (%d,%d)", syn,sum); Break;  Case-1: printf ("\ n (%s, error!)", token); Break; default: printf ("\ n (%d,%s)", SYN, token); }       } while(syn!=0); printf ("\ nthe analysis succeeded \ n"); P=0;     Scaner ();     E (); if(syn==0) printf ("\ n There is no error. \ n"); Elseprintf"\ nthe error occurred. \ n"); }scaner () { for(n=0;n< -; n++) token[n]=NULL; M=0; Sum=0; CH=prog[p++];  while(ch==' ') {ch=prog[p++];} if(ch>='a'&& ch<='Z')           { while(ch>='a'&& ch<='Z'|| ch>='0'&& ch<='9') {token[m++]=ch; CH=prog[p++]; } SYN=Ten;p--;  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*Ten+ (ch-'0'); ch=prog[p++];} Syn= One;p--; }          Else                 Switch(CH) { Case '<': token[m++]=ch; CH=prog[p++]; if(ch=='>') {syn= +; token[m++]=ch;} Else if(ch=='=') {syn= A; token[m++]=ch;} Else{syn= -;p--;}  Break;  Case '>': m=0; token[m++]=ch; CH=prog[p++]; if(ch=='=') {syn= -; token[m++]=ch;} Else{syn= at;p--;}  Break;  Case ':': m=0; token[m++]=ch; CH=prog[p++]; if(ch=='=') {syn= -; token[m++]=ch;} Else{syn= -;p--;}  Break;  Case '+': syn= -; token[0]=ch; Break;  Case '-': syn= -; token[0]=ch; Break;  Case '*': syn= the; token[0]=ch; Break;  Case '/': syn= -; token[0]=ch; Break;  Case '=': syn= -; token[0]=ch; Break;  Case ';': syn= -; token[0]=ch; Break;  Case '(': syn= -; token[0]=ch; Break;  Case ')': syn= -; token[0]=ch; Break;  Case '#': syn=0; token[0]=ch; Break; default: syn=-1; token[0]=ch; }}e () {printf ("E");    T ();    E1 (); }e1 () {printf ("E1"); if(syn== -) {Scaner ();        T ();    E1 (); }    Else {        if(syn!= -&& syn!=0) error (); }} T () {printf ("T");    F (); T1 ();} T1 () {printf ("T1"); if(syn== the) {Scaner ();        F ();    T1 (); }    Else {        if(syn!= -&& syn!=0&& syn!= -) error (); }}f () {printf ("F"); if(syn== -) {Scaner ();        E (); if(syn== -) Scaner (); Elseerror (); }    Else if(syn== One|| syn==Ten) Scaner (); }error () {printf ("\ n (%d,%s) wrong place! \ n", SYN, token);}

C-Language parsing parser