1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// REQUIRES: long_tests
11
12// <random>
13
14// template<class IntType = int>
15// class discrete_distribution
16
17// template<class _URNG> result_type operator()(_URNG& g, const param_type& parm);
18
19#include <random>
20#include <vector>
21#include <cassert>
22
23int main()
24{
25    {
26        typedef std::discrete_distribution<> D;
27        typedef D::param_type P;
28        typedef std::minstd_rand G;
29        G g;
30        D d;
31        double p0[] = {.3, .1, .6};
32        P p(p0, p0+3);
33        const int N = 10000000;
34        std::vector<D::result_type> u(3);
35        for (int i = 0; i < N; ++i)
36        {
37            D::result_type v = d(g, p);
38            assert(0 <= v && v <= 2);
39            u[v]++;
40        }
41        std::vector<double> prob = p.probabilities();
42        for (int i = 0; i <= 2; ++i)
43            assert(std::abs((double)u[i]/N - prob[i]) / prob[i] < 0.001);
44    }
45}
46