example.cpp

/////////////////////////////////////////////////////////////////////////////////
// This file is a C++ wrapper around wyhash: 
// https://github.com/wangyi-fudan/wyhash
// 
// Copyright (c) 2022 by Alain Espinosa.
/////////////////////////////////////////////////////////////////////////////////

// include the required header
#include <wy.hpp>
#include <random>

void main_rand()
{
	// Create a pseudo-random generator
	wy::rand r;

	uint64_t r_value = r();                          // Generate a random number

	// Using direct methods
	double r_uniform01 = r.uniform_dist();           // Generate a random number from the uniform distribution [0, 1)
	uint64_t runiformk = r.uniform_dist(13);         // Generate a random number from the uniform distribution [0, 13)
	double r_uniform_p = r.uniform_dist(1.5, 4.7);   // Generate a random number from the uniform distribution [1.5, 4.7)

	double r_gaussian01 = r.gaussian_dist();         // Generate a random number from the Gaussian distribution with mean=0 and std=1
	double r_gaussian_p = r.gaussian_dist(1.1, 2.3); // Generate a random number from the Gaussian distribution with mean=1.1 and std=2.3

	// Using C++ <random> distributions
	std::uniform_int_distribution<uint64_t> dist(0, 13);
	runiformk = dist(r); // Similar to r.uniform_dist(13) but slower

	std::normal_distribution<double> gdist(1.1, 2.3);
	r_gaussian_p = gdist(r); // Similar to r.gaussian_dist(1.1, 2.3) but slower
}

#include <unordered_map>
#include <iostream>
#include <format>

struct Person
{
	std::string name;
	std::string surname;
};

void main_hash()
{
	// Create random persons
	std::vector<Person> persons;
	for (size_t i = 0; i < 500; i++)
		persons.push_back(Person{ std::string("Person Name") + std::to_string(i), std::string("Surname") });

	// Create hashtable
	std::unordered_map<std::string, Person, wy::hash<std::string>> h;

	// Add persons to the hashtable
	for (size_t i = 0; i < persons.size(); i++)
		h[persons[i].name] = persons[i];

	// Count persons
	size_t persons_found = 0;
	for (size_t i = 0; i < persons.size() * 2; i++)
		persons_found += h.count(std::string("Person Name") + std::to_string(i));

	std::cout << std::format("Found {} persons", persons_found) << std::endl;
}

int main()
{
	main_rand();
	main_hash();

	return 0;
}