program Lab21;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils;
Type
    PStack = ^Element;
    Element = Record
        Data: Char;
        Next: PStack;
    End;
Function Pop(Var Stack: PStack): Char;
Var
    El: Char;
    Top: PStack;
Begin
    Top := Stack;
    El := Stack.Data;
    Top := Stack.Next;
    Stack := Top;
    Pop := El;
End;
Procedure Push(Var Stack: PStack;El: Char);
Var
    Top: PStack;
Begin
    New(Top);
    Top.Data := El;
    Top.Next := Stack;
    Stack := Top;
    Top := Nil;
End;
Function CheckLine(Line: String): Boolean;
Const
    AllowedSymbols = ['+','-','*','/','^','(',')','A'..'Z','a'..'z','0'..'9'];
Var
    IsCorrect: Boolean;
    I: Integer;
Begin
    IsCorrect := True;
    I := 1;
    While IsCorrect and (I <= Length(Line)) do
    begin
        if Not (Line[I] in AllowedSymbols) then
            IsCorrect := False;
        Inc(I);
    end;
    CheckLine := IsCorrect;
End;
Function TakeLine(): String;
Var
    IsCorrect: Boolean;
    Line: String;
Begin
    repeat
        IsCorrect := True;
        ReadLn(Line);
        if (Length(Line) < 1) or (Length(Line) > 1024) then
        begin
            WriteLn('Недопустимая длина строки!');
            IsCorrect := False;
        end;
        if IsCorrect and Not CheckLine(Line) then
        begin
            WriteLn('Строка содержит недопустимые символы!');
            IsCorrect := false;
        end;
    until IsCorrect;
    TakeLine := Line;
End;
Function MakePostfix(Infix: String): String;
Const
    Symbols = ['A'..'Z','a'..'z','0'..'9'];
    Plus = ['+','-'];
    Mult = ['*','/'];
Var
    I: Integer;
    Stack: PStack;
    Postfix: String;
    IsOpen: Boolean;
Begin
    Postfix := '';
    New(Stack);
    Stack.Data := '$';
    Stack.Next := Nil;
    IsOpen := False;
    For I := 1 to High(Infix) do
    begin
        if Infix[I] in Symbols then
            Postfix := Postfix + Infix[I]
        else if (Infix[I] in Plus) and Not(Stack.Data in Mult) and Not(Stack.Data in Plus) and (Stack.Data <> '^') then
            Push(Stack, Infix[I])
        else if (Infix[I] in Plus) and (Stack.Data in Plus) then
        begin
            Postfix := Postfix + Pop(Stack);
            Push(Stack, Infix[I]);
        end
        else if (Infix[I] in Plus) and ((Stack.Data in Mult) or (Stack.Data = '^')) then
        begin
            while (Stack.Data <> '$') and (Stack.Data <> '(') do
                Postfix := Postfix + Pop(Stack);
            Push(Stack, Infix[I]);
        end
        else if (Infix[I] in Mult) and Not (Stack.Data in Mult) and (Stack.Data <> '^') then
            Push(Stack, Infix[I])
        else if (Infix[I] in Mult) and (Stack.Data in Mult) then
        begin
            Postfix := Postfix + Pop(Stack);
            Push(Stack, Infix[I]);
        end
        else if (Infix[I] in Mult) and (Stack.Data = '^') then
        begin
            while (Stack.Data <> '$') and (Stack.Data <> '(') do
                Postfix := Postfix + Pop(Stack);
            Push(Stack, Infix[I]);
        end
        else if Infix[I] = '^' then
            Push(Stack, Infix[I])
        else if Infix[I] = '(' then
            Push(Stack, Infix[I])
        else if Infix[I] = ')' then
        begin
            while (Stack.Data <> '(') and (Stack.Data <> '$') do
                Postfix := Postfix + Pop(Stack);
            Pop(Stack);
        end;
    end;
    while Stack.Data <> '$' do
    begin
        Postfix := Postfix + Pop(Stack);
    end;
    MakePostfix := Postfix;
End;
Procedure ShowRank(Postfix: String);
Const
    Symbols = ['A'..'Z','a'..'z','0'..'9'];
Var
    RankS, RankO, I: Integer;
Begin
    RankS := 0;
    RankO := 0;
    For I := 1 to High(Postfix) do
    begin
        if Postfix[I] in Symbols then
            Inc(RankS)
        else
            Dec(RankO);
    end;
    WriteLn(RankS,' - ',Abs(RankO),' = ',RankS + RankO);
    if RankS + RankO = 1 then
        WriteLn('Выражение верное!')
    else
        WriteLn('Выражение неверное!');
End;
Procedure Main();
Var
    Infix, Postfix: String;
Begin
    WriteLn('Введите выражение в инфиксной записи.');
    Infix := TakeLine();
    Postfix := MakePostfix(Infix);
    WriteLn(Postfix);
    ShowRank(Postfix);
End;
Begin
    Main();
    WriteLn('Нажмите Enter, чтобы продолжить.');
    ReadLn;
End.
 //Преобразовать выражение в обратную польскую запсиь используя стек со скобками и двойными степенями и !!!!считаем ранг!!!!