C++ 标准库 —— random

#include <random>

引擎（engine）与分布（distribution）

std::default_random_engine dre;

std::uniform_int_distribution<int> di(10, 20);
// 包含端点
std::uniform_real_distribution<double> dr(10, 20);
// 不包含右端点

std::default_random_engine dre;
std::uniform_int_distribution di(10, 20);
for (int i = 0; i < 20; ++i)
cout << di(dre) << " ";
cout << endl;

std::uniform_real_distribution dr(10, 20);
for (int i = 0; i < 20; ++i)
cout << dr(dre) << " ";
cout << endl;

std::vector<int> v = {1, 2, 3, 4, 5, 6, 7, 8, 9};
std::shuffle(v.begin(), v.end(), dre);
copy(v.begin(), v.end(), ostream_iterator<int>(cout, " "));
cout << endl;