000
08.06.2005, 15:50 Uhr
~Demson
Gast
|
Ich habe ein Programm geschrieben
aber ich ich bekomme immer merhre fehler .
der sollt ein dantein Txt öffnen dann rechnen .
Mein Programm Lautet .
| C++: |
#include <iostream>
#include <sstream>
#include <string>
#include <map>
#include <cctype>
using namespace std;
void main ()
{
ifstream in("Formel.txt");
while(!in.eof())
{
char ch;
in>>ch;
cout<<ch;
};
return 0;
}
enum Token_value {
NAME, NUMBER, END, INC, DEC,
PLUS='+', MINUS='-', MUL='*', DIV='/',
PRINT=';', ASSIGN='=', LP='(', RP=')'
};
Token_value curr_tok = PRINT;
double number_value;
string string_value;
double expr(bool );
double term(bool );
double error(const string&);
double prim(bool );
Token_value get_token();
map<string, double> table;
double expr(bool get)
{
double left = term(get);
for(;;)
switch(curr_tok) {
case PLUS:
left += term(true);
break;
case MINUS:
left -= term(true);
break;
default:
return left;
}
}
double term(bool get)
{
double left = prim(get);
for(;;)
switch(curr_tok) {
case MUL:
left *= prim(true);
break;
case DIV:
if (double d = prim(true)) {
left /=d;
break;
}
return error("divide by 0");
default:
return left;
}
}
double prim(bool get)
{
if(get) get_token();
switch(curr_tok) {
case NUMBER:
{
double v = number_value;
get_token();
return v;
}
case NAME:
{
double& v = table[string_value];
get_token();
if (curr_tok == ASSIGN)
v = expr(true);
if (curr_tok == INC) //r++;
v = v+1;
if (curr_tok == DEC) //r++;
v = v-1;
return v;
}
case INC:
return prim(true)+1;
case DEC:
return prim(true)-1;
case MINUS:
return -prim(true);
case LP:
{
double e=expr(true);
if(curr_tok != RP) return error(" ')' expected");
get_token();
return e;
}
default:
return error("primary expected");
}
}
Token_value get_token()
{
char ch;
do {
if(!cin.get(ch)) return curr_tok = END;
} while(ch!='\n' && isspace(ch));
switch(ch) {
case ';':
case '\n':
return curr_tok=PRINT;
case 0:
return curr_tok=END;
case '+': // added for ++name and name++
{
char c;
if ( cin.get(c) && c == '+' )
return curr_tok=INC;
cin.putback(c);
return curr_tok=Token_value(ch);
}
case '-':
{
char c;
if ( cin.get(c) && c == '-' )
return curr_tok=DEC;
cin.putback(c);
return curr_tok=Token_value(ch);
}
case '*':
case '/':
case '(':
case ')':
case '=':
return curr_tok=Token_value(ch);
case '0':case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '.':
cin.putback(ch);
cin >> number_value;
return curr_tok=NUMBER;
default:
if (isalpha(ch)){
string_value=ch;
while(cin.get(ch) && isalnum(ch)) string_value.push_back(ch);
cin.putback(ch);
return curr_tok=NAME;
}
error("bad token");
return curr_tok=PRINT;
}
}
int no_of_errors;
double error(const string& s)
{
no_of_errors++;
cerr << "error: " << s << '\n';
return 1;
}
istream* input;
int main(int argc, char* argv[])
{
switch(argc) {
case 1:
input = &cin;
break;
case 2:
input = new istringstream(argv[1]);
break;
default:
error("too man arguments");
return 1;
}
table["pi"] = 3.141;
table["e"] = 2.718;
while(cin) {
get_token();
if( curr_tok == END) break;
if( curr_tok == PRINT) continue;
cout << expr(false) << '\n';
}
if(input != &cin) delete input;
return no_of_errors;
}
|
Fehler :
| Code: |
Projetarbeit.cpp:22: error: `main' must return `int'
Projetarbeit.cpp: In function `int main(...)':
Projetarbeit.cpp:24: error: variable `std::ifstream in' has initializer but
incomplete type
Projetarbeit.cpp: In function `int main(int, char**)':
Projetarbeit.cpp:213: error: declaration of C function `int main(int, char**)'
conflicts with
Projetarbeit.cpp:22: error: previous declaration `int main(...)' here
|
mod edit: benutze die Board Tags selber :twisted:
Dieser Post wurde am 08.06.2005 um 19:03 Uhr von Pablo editiert. |
