lab 2.4 delphi

Program Lab2task4;

{$APPTYPE CONSOLE}

uses
  SysUtils;

Type
    MyArray = Array of Integer;

Function ChoiceCheck() : Integer;
Var
    Choice: Integer;
    IsCorrect: Boolean;
Begin
    Repeat
        IsCorrect:=True;
        Try
            Readln(Choice);
        Except
            Writeln('Error! Input a number');
            IsCorrect := False;
        End;
        If (IsCorrect And ((Choice < 1) Or (Choice > 2))) Then
        Begin
            Writeln('Error! Input 1 or 2');
            IsCorrect := False;
        End;
    Until  (IsCorrect);
    ChoiceCheck := Choice;
End;

Function InputCheck(): Integer;
Var
    IsCorrect: Boolean;
    N: Integer;
Begin
    Writeln('Input the number of elements');
    Repeat
        IsCorrect:=True;
        Try
            Readln(N);
        Except
            Writeln('Error! Input a number');
            IsCorrect:=False;
        End;
        If (IsCorrect And(N<2)) Then
        Begin
            IsCorrect:=False;
            Writeln('Error! Input a number greater than 1');
        End;
    Until  (IsCorrect);
    InputCheck:=N;
End;

Function InputCheckArray(Var N: Integer; Arr: MyArray): MyArray;
Var
    I: Integer;
    IsCorrect: Boolean;
Begin
    For I:=0 To N Do
    Repeat
        IsCorrect:=True;
        Writeln('Input an element');
        Try
            Readln(Arr[I]);
        Except
            Writeln('Error! Input a number');
            IsCorrect:=False;
        End;
    Until  (IsCorrect);
    InputCheckArray := Arr;
End;

Function CheckInputFilePath(): String;
Var
    Path: String;
    IsCorrect: Boolean;
    InputFile: File;
Begin
    Repeat
        Writeln('Input path to the file');
        IsCorrect := True;
        Readln(Path);
        If (Not(FileExists(Path))) Then
        Begin
            IsCorrect := False;
            Writeln('Could not find the file');
        End;
        If (IsCorrect) Then
        Begin
            Try
                AssignFile(InputFile, Path);
                ReSet(InputFile);
            Except
                IsCorrect := False;
                Writeln('Could not open the file');
            End;
        End;
    Until (IsCorrect);
    CloseFile(InputFile);
    CheckInputFilePath := Path;
End;

Function FileCheckArray() : MyArray;
Var
    Arr: MyArray;
    InputFile: TextFile;
    I, N: Integer;

    Path: String;
    IsCorrect: Boolean;
Begin
    Repeat
        Path := CheckInputFilePath();
        IsCorrect := True;
        AssignFile(InputFile, Path);
        Try
            Reset(InputFile);
        Except
            Writeln('Could not open the file');
            IsCorrect := False;
        End;
            Try
            Readln(InputFile, N);
        Except
            IsCorrect := False;
            Writeln ('The data is incorrect');
        End;
        If (N < 2) Then
        Begin
            IsCorrect := False;
            Writeln ('The data is incorrect');
        End;
        If (IsCorrect) Then
        Begin
            SetLength(Arr, N);
            Dec(N);
            For I := 0 To N Do
                Try
                    Read(InputFile, Arr[I]);
                Except
                    IsCorrect := False;
                    Writeln('The data is incorrect');
                End;
            If (Not(EoF(InputFile))) Then
            Begin
                IsCorrect := False;
                Writeln ('The data is incorrect');
            End;
        End;
        Writeln(High(Arr));
    Until (IsCorrect);
    Close(InputFile);
    FileCheckArray := Arr;
End;

Function InputChoice (Var N: Integer; Arr: MyArray): MyArray;
Var
    Choice: Integer;
Begin
    Writeln('Choose input option: ', #10, '1.Input from console', #10,
            '2.Input from file');
    Choice := ChoiceCheck();
    If (Choice = 1)  Then
    Begin
        N := InputCheck();
        SetLength(Arr, N);
        Dec(N);
        Arr := InputCheckArray(N, Arr);
    End
    Else
        Arr := FileCheckArray();
    InputChoice := Arr;
End;

Procedure Sum(N: Integer; Arr, SumArr: MyArray);
Var
    I: Integer;
Begin
    Dec(N);
    For I:=0 to N Do
    SumArr[I]:=Arr[I]+Arr[I+1];
End;

Function FindMax(SumArr: MyArray): Integer;
Var
    I, Max: Integer;
Begin
    Max:=SumArr[0];
    For I:=0 To High(SumArr) Do
    If (SumArr[I]>Max) Then
    Max:=SumArr[I];
    FindMax:=Max;
End;

Function CheckOutputFilePath(): String;
Var
    Path: String;
    IsCorrect: Boolean;
    OutputFile: File;
Begin
    Writeln('Input file path and the name of the file for', #10, 'example, Ñ:\Projects\Number\FileName.txt. If the ', #10, 'file does not exist, then it will be created', #10,'automatically in the root folder of the program');
    IsCorrect := True;
    Readln(Path);
    If (Not(FileExists(Path))) Then
    Begin
        IsCorrect := False;
        Writeln('Could not find the file');
    End;
    If (IsCorrect)Then
    Try
        AssignFile(OutputFile, Path);
        ReSet(OutputFile);
    Except
        IsCorrect := False;
        Writeln('Could not open the file');
    End;
    If (Not(IsCorrect)) Then
    Begin
    Writeln ('File will be created in the root folder of the program');
    Path := 'Result.txt';
    End
    Else
    CloseFile(OutputFile);
    CheckOutputFilePath := Path;
End;

Procedure OutputMax(Max: Integer);
Begin
    Writeln(Max);
End;

Procedure OutputFile (Var Max: Integer);
Var
    Path: String;
    OutputFile: TextFile;
Begin
    Path := CheckOutputFilePath();
    AssignFile (OutputFile, Path);
    ReWrite(OutputFile);
    Writeln(OutputFile, Max);
    Close(OutputFile);
End;

Procedure OutputChoice (Var Max: Integer);
Var
    Choice: Integer;
Begin
    Writeln('Choose output option: ', #10, '1.Output through console', #10,
              '2.Output through file');
    Choice := ChoiceCheck();
    If (Choice = 1) Then
    OutputMax (Max)
    Else
    OutputFile(Max);
End;

Var
    Arr, SumArr: MyArray;
    N, Max: Integer;
Begin
    N := 0;
    Arr := InputChoice (N, Arr);
    N := High(Arr);
    SetLength(SumArr, N);
    Sum(N, Arr, SumArr);
    Max:=FindMax(SumArr);
    OutputChoice(Max);
    Readln
End.