#include <iostream>
#include <vector>
#include <string>
#include <chrono>
#include <random>

std::vector<std::wstring> MakeIntSequence(int size)
{
   std::random_device rd;  //Will be used to obtain a seed for the random number engine
   std::mt19937 gen(rd()); //Standard mersenne_twister_engine seeded with rd()
   std::uniform_int_distribution<> distrib(0, std::numeric_limits<int>::max());
   std::vector<std::wstring> v;
   v.reserve(size);
   for (int i = 0; i < size; ++i)
   {
      v.push_back(std::to_wstring(distrib(gen)));
   }
   return v;
}

int ParseInt(const std::wstring& wstr)
{
   int res{};
   for (auto d : wstr)
   {
      if ('0' <= d && d <= '9')
      {
         res = res * 10 + d - '0';
      }
      else
      {
         throw std::out_of_range("'" + std::to_string(d) + "': Symbol is out of range");
      }
   }
   return res;
}

int main()
{
   namespace tm = std::chrono;

   const auto vals = MakeIntSequence(0x4000000);

   const auto t0 = tm::steady_clock::now();

   int hash{};
   for (const auto& val : vals)
   {
      hash ^= ParseInt(val);
   }
   const auto dt = tm::duration_cast<tm::milliseconds>(tm::steady_clock::now() - t0);

   std::cout << "Hash = " << std::hex << hash << std::endl;
   std::cout << "Processing time: " << std::dec << dt.count() << "ms" << std::endl;
}