ガチャシミュテスト

gistfile1.txt

cmake_minimum_required(VERSION 3.1)
project(gacha_yen_simulate)

find_package(OpenMP REQUIRED)

add_executable(gacha main.cpp)
target_link_libraries(gacha OpenMP::OpenMP_CXX)

main.cpp

#include <iostream>
#include <random>
#include <algorithm>
#include <cmath>
#include <cassert>
#include <utility>
#include <vector>
#include <omp.h>

struct Person {
  unsigned long int max_yen = 0;
  unsigned int gacha_times = 0;
  unsigned int get_number = 0;
  unsigned int tenjo_times = 0;
  unsigned int goal = 1;
};

int main() {
  constexpr size_t LEN = 100000;
  constexpr double PROB = 0.005;
  constexpr unsigned long int MAX_YEN = 100000;
  constexpr unsigned int PRICE = 300;
  std::vector<Person> num(LEN);

  assert(PROB > 0);
  assert(PROB <= 1);
  for (auto& it: num) {
    it.max_yen = MAX_YEN;
  }

  std::random_device seed_gen;
  std::mt19937_64 random_engine(seed_gen());
  std::uniform_real_distribution<> rand;
#pragma omp parallel for
  for (long int i=0;i<num.size();i++) {
    while(true) {
      num[i].gacha_times += 1;
      auto gacha = rand(random_engine);
      if (gacha <= PROB) {
        num[i].get_number += 1;
        break;
      }
      if ((num[i].gacha_times * PRICE) >= num[i].max_yen) {
        break;
      }
    }
  }

  std::cout << std::endl;
  std::sort(num.begin(), num.end(), [](const Person& lt, const Person& rt){ return lt.gacha_times < rt.gacha_times; });
  double median;
  double mean;
  if ((std::round(LEN/2.0)*2) == LEN) {
    median = (num[LEN/2].gacha_times + num[LEN/2+1].gacha_times) / 2.0;
  } else {
    median = num[static_cast<unsigned int>(std::round(LEN/2.0)+1)].gacha_times;
  }
  {
    unsigned long int total = 0;
    for (const auto& i: num) {
      total += i.gacha_times;
    }
    mean = static_cast<double>(total) / LEN;
  }
  auto over_s = std::count_if(num.begin(), num.end(), [&](const Person& v){ return v.gacha_times * PRICE >= v.max_yen; });
  std::cout << "SIZE:" << num.size() << std::endl;
  std::cout << "MEDIAN TIMES:" << median << " YEN:" << median * PRICE << std::endl;
  std::cout << "MEAN TIMES:" << mean << " YEN:" << mean * PRICE << std::endl;
  std::cout << "MIN TIMES:" << num.begin()->gacha_times << " YEN:" << num.begin()->gacha_times * PRICE << std::endl;
  std::cout << "MAX TIMES:" << (--num.end())->gacha_times << " YEN:" << (--num.end())->gacha_times * PRICE << std::endl;
  std::cout << "OVER: " << over_s << std::endl;
  std::cout << std::endl;

  return 0;
}

out.txt

> (Measure-Command { .\Debug\gacha.exe | Write-Host }).TotalSeconds

SIZE:100000
MEDIAN TIMES:138 YEN:41400
MEAN TIMES:161.513 YEN:48454
MIN TIMES:1 YEN:300
MAX TIMES:334 YEN:100200
OVER: 18746

0.8822166