Concatenate unique value separated by comma in two string in C++ - c++

Question

CString s;
int res = 0;
char *existing;
char *current;
existing = strtok(urls, ",");
current = strtok(storedurls, ",");
while (existing != NULL)
{
while (current != NULL)
{
res = strcmp(existing, current);
if (res == 0) continue;
s.Append(current);
current = strtok(NULL, ",");
if (current != NULL) s.Append(",");
}
existing = strtok(NULL, ",");
}
strcat(urls, s);
We have a string of storedurl L("url1,url2,url3") and urls L("url3,url5") and I want to store the unique urls from both string and get a single output as L("url1,url2,url3,url5")

Answer 1

Stop using C-style string functions in C++ and get acquainted with the C++ Standard Library.
#include <algorithm>
#include <vector>
#include <string>
#include <sstream>
#include <iostream>
std::vector<std::string> split(std::string const& src, char delim = ',')
{
std::vector<std::string> dst;
std::stringstream ss{ src };
std::string tmp;
while (std::getline(ss, tmp, delim))
dst.push_back(tmp);
return dst;
}
int main()
{
std::string foo{ "url1,url2,url4" };
std::string bar{ "url2,url3,url5" };
auto foo_urls{ split(foo) };
auto bar_urls{ split(bar) };
std::vector<std::string> unique_urls{ foo_urls.begin(), foo_urls.end() };
unique_urls.reserve(foo_urls.size() + bar_urls.size());
unique_urls.insert(unique_urls.end(), bar_urls.begin(), bar_urls.end());
std::sort(unique_urls.begin(), unique_urls.end());
unique_urls.erase(std::unique(unique_urls.begin(), unique_urls.end()), unique_urls.end());
for (auto const& url : unique_urls)
std::cout << url << '\n';
}

Answer 2

DWORD res = 0;
CString existingUrls = urls;
CString curUrls;
CString curItemInExitingUrl;
CString curItemInCurUrl;
CString urlsToAdd;
while (!existingUrls.IsEmpty()) {
CWinLogFile::GetTok(existingUrls, _T(","), curItemInExitingUrl);
curUrls = src.urls;
while (!curUrls.IsEmpty()) {
CWinLogFile::GetTok(curUrls, _T(","), curItemInCurUrl);
if (curItemInExitingUrl.Compare(curItemInCurUrl)==0)
{
res = 1;
}
}
if (res == 0)
{
urlsToAdd.Append(curItemInExitingUrl);
urlsToAdd.AppendChar(',');
}
else
res = 0;
}
urlsToAdd.Append(src.urls);
Found the solution for my posted question. Where urls & src.urls are two comma separated values of urls. Thanks.