Program Project9;

{$APPTYPE CONSOLE}

uses
  SysUtils;

type
   MatrixType = array of array of Integer;
   TArr = array of Real;

function SizeOfMatrix(var MyFile: TextFile): Integer;
var
   Numb, n, NumbEx, Temp: Integer;
   IsCorrect, FirstIt: Boolean;
begin
   n := 0;
   FirstIt := True;
   IsCorrect := True;
   while (not Eof(MyFile)) and IsCorrect do
   begin
      NumbEx := Numb;
      Numb := 0;
      while not Eoln(MyFile) do
      begin
         Inc(Numb);
         Read(MyFile, Temp);
      end;
      if NumbEx <> Numb then
         IsCorrect := False;
      if FirstIt then
      begin
         IsCorrect := True;
         FirstIt := False;
      end;
      Inc(n);
      Readln(MyFile);
   end;
   if (Numb = n) and IsCorrect then
      SizeOfMatrix := n
   else
      SizeOfMatrix := 0;
   Reset(MyFile);
end;

procedure ReadFileName(var MyFile: TextFile);
var
   FName: string;
   CorrectName: Boolean;
begin
   Writeln('Enter a file name for data entry in the format Name.txt');
   repeat
      Readln(FName);
      if FileExists(FName) then
         CorrectName := True
      else
      begin
         Writeln('The file name was entered incorrectly. Try again. Example: Name.txt');
         CorrectName := False;
      end;
   until CorrectName;
   AssignFile(MyFile, FName);
   Reset(MyFile);
end;

function IsTheMatrixCorrect(var MyFile: TextFile): Boolean;
var
   Number: Integer;
   TrueMatrix, IsValidInput: Boolean;
begin
   TrueMatrix := True;
   while (not Eof(MyFile)) do
   begin
      try
         read(MyFile, Number)
      except
         TrueMatrix := False
      end;
   end;
   if Eof(MyFile) then
      IsValidInput := True
   else
      Writeln('File is empty.');
   Reset(MyFile);
   IsTheMatrixCorrect := TrueMatrix;
end;

procedure ReadMatrix(var Matrixx: MatrixType; var MyFile: TextFile; n: Integer);
var
   i, j: Integer;
   FName: string;
begin
   for i := 0 to n - 1 do
      for j := 0 to n - 1 do
         Read(MyFile, Matrixx[i, j]);
   Reset(MyFile);
end;

procedure FindMax(const Matrixx: MatrixType; n, iFMax, jFMax, iSMax, jSMax: Integer);
var
   FirstMax, SecondMax, i, j: Integer;
begin
   FirstMax := Matrixx[0][0];
   iFMax := 0;
   jFMax := 0;
   for i := 0 to n do
   begin
      for j := 0 to n do
         if (Matrixx[i][j] > FirstMax) then
         begin
            FirstMax := Matrixx[i][j];
            iFMax := i;
            jFMax := j;
         end;
   end;
   SecondMax := Matrixx[0][0];
   iSMax := 0;
   jSMax := 0;
   for i := 0 to n do
   begin
      for j := 0 to n do
         if ((Matrixx[i][j] > SecondMax) and((i <> iFMax) or (j <> jFMax))) then
         begin
            FirstMax := Matrixx[i][j];
            iSMax := i;
            jSMax := j;
         end;
   end;

end;

procedure MatrixOutput(const Matrixx: MatrixType; n: Integer);
var
   i, j: Integer;
begin
   for i := 0 to n - 1 do
   begin
      for j := 0 to n - 1 do
         Write(Matrixx[i, j], ' ');
      Writeln;
   end;
   Writeln;
end;

procedure MaxFindOutput(const Matrixx: MatrixType; n, iFMax, jFMax, iSMax, jSMax: Integer);
var
   i, j: Integer;
begin
   for i := 0 to n - 1 do
   begin
      for j := 0 to n - 1 do
         Writeln(Matrixx[iFMax][jFMax]);
         Writeln(Matrixx[iSMax][jSMax]);
      Writeln;
   end;
   Writeln;
end;


procedure ReadFileOutputName(var MyFile: TextFile);
var
   NewFName: string;
   CorrectName: Boolean;
begin
   Writeln('Enter a file name for data entry in the format Name.txt');
   repeat
      Readln(NewFName);
      if Copy(NewFName, length(NewFName) - 3, 4) = '.txt' then
         CorrectName := True
      else
      begin
         Writeln('The file name was entered incorrectly. Try again. Example: Name.txt');
         CorrectName := False;
      end;
   until CorrectName;
   AssignFile(MyFile, NewFName);
   Rewrite(MyFile);
end;

procedure WriteToFile(const Matrixx: MatrixType; n, iFMax, jFMax, iSMax, jSMax: Integer; var NewFile: TextFile);
var
   i: Integer;
begin
   for i := 0 to n - 1 do
   begin
      Write(NewFile, Matrixx[iFMax][jFMax]);
      Write(NewFile, Matrixx[iSMax][jSMax]);
      Write(NewFile, ' ');
   end;
   CloseFile(NewFile);
   Writeln('Saved to file. ');
end;


var
   Matrixx: MatrixType;
   Size, iFirstMax,jFirstMax ,iSecondMax, jSecondMax: Integer;
   MyTFile: TextFile;
   MyTFileName: string;
   CorrectMatr: Boolean;
   Mass: TArr;

begin
   Writeln('This program finds the arithmetic mean of the positive elements of each column of the square matrix.');
   repeat
      ReadFileName(MyTFile);
      CorrectMatr := IsTheMatrixCorrect(MyTFile);
      if CorrectMatr = True then
      begin
           Writeln('Given matrix:');
         Size := SizeOfMatrix(MyTFile);
         SetLength(Matrixx, Size, Size);
         ReadMatrix(Matrixx, MyTFile, Size);
         CloseFile(MyTFile);
         MatrixOutput(Matrixx, Size);
         SetLength(Mass, Size);
         FindMax(Matrixx, Size, iFirstMax, iSecondMax, jFirstMax, jSecondMax );
         Writeln(' Max elemets are: ');
         MaxFindOutPut(Matrixx, Size, iFirstMax, iSecondMax, jFirstMax, jSecondMax);
         ReadFileOutputName(MyTFile);
         WriteToFile(Matrixx, Size, iFirstMax, iSecondMax, jFirstMax, jSecondMax);
      end
      else
      begin
         CorrectMatr := False;
      Writeln('The name of the matrix inputs incorrect. Try again. Example: Name.txt');
      end;
   until CorrectMatr;
   Readln;
end.