Hilfe benötigt

Ich habe folgendes Programm:

// depth of a tree

// Grammar:
// Tree = '(' Branch { Branch } ')'
// Branch = Label [ Tree ]
// Label = 'a' | 'b' | ... | 'z'

#include <iostream>

// POST: leading whitespace characters are extracted
// from is, and the first non-whitespace
// character is returned (0 if there is none)
char lookahead (std::istream& is);

// PRE: Tree = '(' Branch { Branch } ')'
// POST: Extracts tree from is and returns its depth
int Tree (std::istream& is)
{
char c;

is >> c; // extract '('

int depth = 0; // int depth = expr1;

while (lookahead (is) != ')')
{
const int bdepth = Branch (is); // const int bdepth = expr2;

if (bdepth > depth) // if (expr3)
{
depth = bdepth; // expr4;
}
}
is >> c; // extract ')'

return depth;
}

// PRE: Branch = Label [ Tree ]
// POST: Extracts single branch from is and returns
// its depth
int Branch (std::istream& is)
{
char c;

is >> c; // extract label

if (lookahead (is) == '(')
{
return 1 + Tree (is); // return expr5;
}
return 1;
}

int main()
{
const int depth = Tree (std::cin);

std::cout << "Longest stored word has length " << depth;

return 0;
}

Mit folgender Fehlermeldung:

./Root/depth_of_a_tree.cpp: In function 'int Tree(std::istream&)':
./Root/depth_of_a_tree.cpp:27:37: error: 'Branch' was not declared in this scope
const int bdepth = Branch(is); // const int bdepth = expr2;
^

Das Problem ist mir bekannt, jedoch weiss ich nicht wie ich es beheben kann.

HarteWare

int Branch (std::istream& is);

forward-deklarieren (vor Tree), so wie bei lookahead.

// PRE: Branch = Label [ Tree ]
// POST: Extracts single branch from is and returns
// its depth
int Branch (std::istream& is);

Dies vor int Tree (.....) ?

Danke schonmal für die schnelle Antwort

elgouddi schrieb:

// PRE: Branch = Label [ Tree ]
// POST: Extracts single branch from is and returns
// its depth
int Branch (std::istream& is);

Dies vor int Tree (.....) ?

Danke schonmal für die schnelle Antwort

Funzt nicht

Evtl. hab ichs probiere grad aus.