ANTICHAT — форум по информационной безопасности, OSINT и технологиям

std::string hello = "Hello World!";
replace(hello, "o", "_");
std::cout << hello << "\n";
выведет: Hell_ W_rld!

и ещё

std::string hello = "Hello Worlld!";
replace(hello, "ll", "$");
std::cout << hello << "\n";
выведет: He$o Wor$d!

#include <iostream>
#include <string>

void replace (std::string& source, std::string findWhat, std::string replaceWith) {
    if (source == "" || findWhat == "")
        return;
    if (source == findWhat) {
        source = replaceWith;
        return;
    }
    size_t findWhatIndex = 0;
    size_t startIndex = 0;
    size_t findLength = findWhat.length();
    bool flag = false;
    for (size_t i = 0; i < source.length(); i++) {
        if (flag) {
            if (source.at(i) == findWhat.at(findWhatIndex) && findWhatIndex < (findLength - 1))
                ++findWhatIndex;
            else if (source.at(i) == findWhat.at(findWhatIndex) && findWhatIndex == (findLength - 1)) {
                source = source.replace(startIndex, findLength, replaceWith);
                findWhatIndex = 0;
                startIndex = 0;
                flag = false;
            }
            else {
                findWhatIndex = 0;
                startIndex = 0;
                flag = false;
            }
        }
        else {
            if (source.at(i) == findWhat.at(0) && findLength == 1)
                source = source.replace(i, 1, replaceWith);
            else if (source.at(i) == findWhat.at(0)) {
                startIndex = i;
                ++findWhatIndex;
                flag = true;
            }
        }
    }
}

 type

  TPas = class
  private
    FNum: Integer;
    FValues: String;
  public
    property Num: Integer read FNum write FNum;
    property Values: String read FValues write FValues;
  end;

  TPasses = array of TPas;

 procedure TForm1.FormCreate(Sender: TObject);
var
  i: Integer;
begin
  StringGrid1.Cells[0, 0] := '№';
  StringGrid1.Cells[1, 0] := 'набор значений';
  for i := 1 to StringGrid1.RowCount do
    StringGrid1.Cells[0, i] := IntToStr(i);

procedure TForm1.Edit2Change(Sender: TObject);
var
  i: Integer;
begin
  StringGrid1.RowCount := StrToInt(Edit2.Text) +1;
  for i := 1 to StringGrid1.RowCount do
    StringGrid1.Cells[0, i] := IntToStr(i);
end;

 procedure TForm1.AddToFile(rec: String);
var
  AFile: TextFile;
begin
  if Length(rec)= StringGrid1.RowCount-1 then
  begin
    Label1.Caption := rec;
    Application.ProcessMessages;
    Assignfile(AFile,Edit3.Text);
    if fileexists(Edit3.Text) = false then
      rewrite(AFile)
    else Append(AFile);
    writeln(AFile, rec);
    closefile(AFile);
  end;
end;

function TForm1.GetPasses: TPasses;
var
  i: Integer;
  Pas: TPas;
begin
  SetLength(Result, StringGrid1.RowCount-1);
  for i := 1 to StringGrid1.RowCount - 1 do
  begin
    Pas := TPas.Create;
    Pas.Num := StrToInt(StringGrid1.Cells[0, i])-1;
    Pas.Values := StringGrid1.Cells[1, i];
    Result[i-1] := Pas;
  end;
end;

procedure TForm1.GetWords(srt: String; Num: Integer);
var
  i: Integer;
  ss: TPasses;
  s: String;
begin
  ss := GetPasses;
  for i := 1 to Length(ss[Num].Values) do
  begin
    s := srt + ss[Num].Values[i];
    AddToFile(s);
    if ((Num+1) <= (StringGrid1.RowCount-2)) then
      GetWords(s, Num+1);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  GetWords('', 0);
end;