#include <cmath>

#include <fmt/ranges.h>

#include <functional>

#include <iomanip>

#include <iostream>

#include <map>

#include <random>

#include <vector>

using namespace std;

int randInt(const int low, const int high)

{

static default_random_engine re{};

using Dist = uniform_int_distribution<int>;

static Dist uid{};

return uid(re, Dist::param_type{low, high});

}

/**

* Your Solution object will be instantiated and called as such:

* Solution* obj = new Solution(nums);

* vector<int> param_1 = obj->reset();

* vector<int> param_2 = obj->shuffle();

*/

class Solution

{

// Seed with a real random value, if available

default_random_engine re{std::random_device{}()};

public:

const vector<int> original;

vector<int> arr; // for return

Solution(vector<int> &nums)

: original{nums}

, arr{nums}

{

// std::ios_base::sync_with_stdio(false);

// std::cin.tie(nullptr);

}

vector<int> reset()

{

arr = original;

return arr;

}

vector<int> shuffle()

{

for (int i = arr.size() - 1; i > 0; --i) {

const auto idx = std::uniform_int_distribution<int>(0, i)(re);

std::swap(arr[i], arr[idx]);

}

return arr;

}

void randomNumHistogram(const int range)

{

// Reference

// https://en.cppreference.com/w/cpp/numeric/random

// https://www.stroustrup.com/C++11FAQ.html#std-random

std::map<int, int> hist;

for (int n = 0; n != 10000; ++n)

++hist[std::uniform_int_distribution<int>(0, range)(re)];

std::cout << "Uniform distribution "

<< ":\n"

<< std::fixed << std::setprecision(1);

for (auto [x, y] : hist)

std::cout << std::setw(2) << x << ' ' << std::string(y / 200, '*') << '\n';

}

};

int main()

{

vector nums{1, 2, 3, 4, 5};

Solution obj(nums);

vector<int> param_1 = obj.shuffle();

vector<int> param_2 = obj.reset();

fmt::print("nums: {}\n", fmt::join(nums, ", "));

fmt::print("shuffle: {}\n", fmt::join(param_1, ", "));

fmt::print("reset: {}\n", fmt::join(param_2, ", "));

// obj.randomNumHistogram(nums.size());

}