C Programming Language 4-6 lesson question reference answer incorrect

4-6 if the use of official "matching" (in fact, other people wrote) reference books, the answer code is not correct, can not successfully achieve the goal. However, slightly modified to:

First, the global definition of the Var parameter (the name itself), the main code is consistent with the recommendation:

int var;//defines VAR here in main () {int type,i;
    Double op1,op2,v;
    Char S[MAXOP];
    void clean (void);

    Double vars[26];
    for (i=0;i<26;i++) vars[i]=0.0;
            while ((Type=getop (s))!=eof) {switch (type) {case Number:push (atof (s));
        Break
            Case ' + ': Push (Pop () +pop ());
        Break
            Case Func:mathfunc (s);
        Break
            Case ' * ': Push (Pop () *pop ());
        Break
            Case '-': Op2=pop ();
            Push (pop ()-op2);
        Break
            Case '/': Op2=pop ();
            if (op2!=0.0) push (pop ()/op2);
            else printf ("Error:zero divisor\n");
        Break
            Case '% '://Modulo addition operation Op2=pop ();
            if (op2!=0.0) push (Fmod (pop (), OP2));
            else printf ("Divisor cannot be 0\n");
        Break Case ' \ n ': printf ("\t%.8g\n",Pop ());
        Break
            Case '? '://print stack top element op2=pop ();
            printf ("\t%.8g\n", OP2);
            Push (OP2);
        Break
            Case ' C '://Empty stack clean ();
        Break
            Case ' s ': Op1=pop ();
            Op2=pop ();
            Push (OP1);
            Push (OP2);
        Break
            Case ' = ': Pop ();
                if (var>= ' a ' &&var<= ' Z ') {vars[var-' a ']=pop ();
            else printf ("Record variable Failed");
        Break
            Default:if (type>= ' a ' &&type<= ' Z ') push (vars[type-' a '));
            else if (type== ' V ') push (v);
            else printf ("Error:unknown command%s\n", s);
        Break
} return 0; }

Next, modify the getop to increase the capital check:

int Getop (char s[]) {int i,c; while ((S[0]=c=getch ()) = = ' | |
    c== ' t ');
    S[1]= ' ";
    i=0;
        if (Isupper (c)) {//increase the capital letter detection Var=c;
    return C;
        } if (Islower (c)) {int p=c;
        Here c is changed, so it needs to be staged with a new variable, otherwise the expected result is not achieved while (Islower (S[++i]=c=getch ()));
        S[i]= ' ";
            if (c!=eof) {ungetch (c);
        } if (strlen (s) >1) {return FUNC;
        } else{return p; } if (!isdigit (c) && c!= '. '

    && c!= '-') return C;
                Check here for negative if (c = = '-') {if (IsDigit (S[++i]=c=getch ())) {While isdigit (S[++i]=c=getch ()))
        ; else if ((S[++i]=c=getch ()) = = '. ')
        {while (IsDigit (S[++i]=c=getch ()));
            else{if (c!=eof) Ungetch (c);
            Return '-'; } if (IsDigit (c)) while IsDigit (s[++i]=c=getch ()));
        if (c = = '. ')
    while (IsDigit (S[++i]=c=getch ()));
    S[i]= ' ";
    if (c!=eof) Ungetch (c);
return number; }

OK, but there's more than one way to do it.