不重载运算符 [英] Not overloading operator

问题描述

早上好，我在业余时间做一些Codeforces练习，并且在测试用户是男孩还是女孩时遇到问题，嗯，我的问题不是，我只是演示了代码. 在计算机上编译我的代码时(我在i386上使用3.0.4版本)，我没有收到任何错误，但是Codeforces给了我这个错误

Good day, I'm doing some Codeforces exercises in my free time, and I had a problem to test if the user was a boy or a girl, well, my problem isn't that, i have just demonstrated the code. While compiling my code in my computer ( I'm using version 3.0.4 for i386 ) i get no error, but codeforces gives me this error

program.pas(15,16) Error: Operator is not overloaded: "freq(Char;AnsiString):LongInt;" + "ShortInt"
program.pas(46,4) Fatal: There were 1 errors compiling module, stopping 

这个错误对我来说还不够清楚，因为同一脚本已完美地与我的版本一起编译了. 该平台正在使用(版本3.0.2 i386-Win32).

The error wasn't clear enough to me, as the same script was perfectly compiled with my version. The platform is using ( version 3.0.2 i386-Win32 ).

program A236;
uses wincrt, sysutils;

var
    username : String;


function freq(char: char; username : String): Integer;
var 
   i: Integer;
begin
    freq:= 0;
    for i:= 1 to length(username) do
        if char = username[i] then
            freq:= freq + 1;
            //writeln(freq);        
end; 

function OddUserName(username : String): Boolean;
var
    i, counter: Integer;

begin
    OddUserName:= false; // even
    counter:= 0;
    for i:= 1 to length(username) do 
        if freq(username[i], username) <> 1 then    
            delete(username, i, 1)
        else
            counter:= counter + 1;  
    if counter mod 2 <> 0 then
        OddUserName:= true; // odd
    //writeln(counter); 
    //writeln(OddUserName);                 
end;        

begin
    readln(username);
    if not OddUserName(username) then 
        writeln('CHAT WITH HER!')
    else 
        writeln('IGNORE HIM!'); 


    //readkey();    
end.

错误可能在此行:

function freq(character: char; username : String): Integer;

感谢所有提供帮助的人.

Thanks for everyone who helps.

推荐答案

在函数内部，该函数的名称可以替代使用显式局部变量或Result. freq()和OddUserName()都这样做，但是只有freq()使用函数名作为赋值右侧的操作数. freq := freq + 1; 应该是现代Pascal编译器中的法律声明，请参见为什么我可以在pascal中使用函数名作为变量名称没有定义?.

Inside of a function, the function's name can be used as a substitute for using an explicit local variable or Result. freq() and OddUserName() are both doing that, but only freq() is using the function name as an operand on the right-hand side of an assignment. freq := freq + 1; should be a legal statement in modern Pascal compilers, see Why i can use function name in pascal as variable name without definition?.

但是，错误消息似乎表明失败的编译器正在将语句freg + 1中的freq视为函数类型，而不是局部变量.那可以解释为什么它抱怨不能添加具有函数类型的ShortInt.

However, it would seem the error message is suggesting that the failing compiler is treating freq in the statement freg + 1 as a function type and not as a local variable. That would explain why it is complaining about not being able to add a ShortInt with a function type.

因此，您将不得不使用显式的局部变量(或，如果编译器提供的话，则使用特殊的Result变量)，例如:

So, you will have to use an explicit local variable instead, (or the special Result variable, if your compiler provides that), eg:

function freq(charToFind: char; username : String): Integer;
var 
  i, f: Integer;
begin
  f := 0;
  for i := 1 to Length(username) do
    if charToFind = username[i] then
      f := f + 1;
      //writeln(f);
  freq := f;
end; 

function freq(charToFind: char; username : String): Integer;
var 
  i: Integer;
begin
  Result := 0;
  for i := 1 to Length(username) do
    if charToFind = username[i] then
      Result := Result + 1;
      //writeln(f);
end; 

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