| 26 | /// that can be represented on 'bit_width' size bits. |
| 27 | template<typename RandomEngine> |
| 28 | std::vector<int> MakeRandomSequence(RandomEngine& random_eng, int total_length, |
| 29 | int max_run_length, int bit_width) { |
| 30 | auto NextRunLength = [&]() { |
| 31 | std::uniform_int_distribution<int> uni_dist(1, max_run_length); |
| 32 | return uni_dist(random_eng); |
| 33 | }; |
| 34 | auto IsNextRunRepeated = [&random_eng]() { |
| 35 | std::uniform_int_distribution<int> uni_dist(0, 1); |
| 36 | return uni_dist(random_eng) == 0; |
| 37 | }; |
| 38 | auto NextVal = [bit_width](int val) { |
| 39 | if (bit_width == CHAR_BIT * sizeof(int)) return val + 1; |
| 40 | return (val + 1) % (1 << bit_width); |
| 41 | }; |
| 42 | |
| 43 | std::vector<int> ret; |
| 44 | int run_length = 0; |
| 45 | int val = 0; |
| 46 | int is_repeated = false; |
| 47 | while (ret.size() < total_length) { |
| 48 | if (run_length == 0) { |
| 49 | run_length = NextRunLength(); |
| 50 | is_repeated = IsNextRunRepeated(); |
| 51 | val = NextVal(val); |
| 52 | } |
| 53 | ret.push_back(val); |
| 54 | if (!is_repeated) val = NextVal(val); |
| 55 | --run_length; |
| 56 | } |
| 57 | return ret; |
| 58 | } |
| 59 | |
| 60 | } |