Hello all! I have started studying dfs and it's applications and I was studying topological sorting (https://www.spoj.com/problems/TOPOSORT/). I am stuck at the part to check the graph is Acyclic or not? Can anyone help with any easier way to check this? Thanks!
Пожалуйста, прочтите новое правило об ограничении использования AI-инструментов.
→ Обратите внимание
→ Трансляции
→ Лидеры (рейтинг)
| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | tourist | 4009 |
| 2 | jiangly | 3773 |
| 3 | Radewoosh | 3646 |
| 4 | ecnerwala | 3624 |
| 5 | jqdai0815 | 3620 |
| 5 | Benq | 3620 |
| 7 | orzdevinwang | 3612 |
| 8 | Geothermal | 3569 |
| 8 | cnnfls_csy | 3569 |
| 10 | Um_nik | 3396 |
| Страны | Города | Организации | Всё → |
→ Лидеры (вклад)
| № | Пользователь | Вклад |
|---|---|---|
| 1 | Um_nik | 163 |
| 2 | cry | 161 |
| 3 | maomao90 | 160 |
| 4 | -is-this-fft- | 159 |
| 5 | awoo | 158 |
| 5 | atcoder_official | 158 |
| 7 | adamant | 155 |
| 8 | nor | 154 |
| 9 | maroonrk | 152 |
| 10 | Dominater069 | 149 |
→ Найти пользователя
→ Прямой эфир
Codeforces (c) Copyright 2010-2024 Михаил Мирзаянов
Соревнования по программированию 2.0
Время на сервере: 21.09.2024 22:51:15 (j1).
Десктопная версия, переключиться на мобильную.
При поддержке
I think Kahn's algorithm will be the easiest.
kahn's algorithm : https://www.geeksforgeeks.org/topological-sorting-indegree-based-solution/
Assuming that your topological sorting algorithm terminates regardless of whether the graph is acyclic, you can generate an ordering with the algorithm, and then just check if it's valid. If the ordering is invalid (a node is added before one of its parents), then it has cycles.
How to check if ordering is valid?
I said it in my previous comment.
But also, some algorithms will instead produce an ordering that doesn't contain all of the nodes. It really depends on what algorithm you use.
Code