141. linked list cycle#1
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141. Linked List Cycle
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nodchip
reviewed
Jul 2, 2025
| class Solution { | ||
| public: | ||
| bool hasCycle(ListNode *head) { | ||
| std::set<ListNode*> visited_nodes ; |
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visited_nodes と ; の間のスペースは消すことをお勧めいたします。
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| bool hasCycle(ListNode *head) { | ||
| std::set<ListNode*> visited_nodes ; | ||
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| while (head != NULL) { |
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ご指摘ありがとうございます。
https://cpprefjp.github.io/lang/cpp11/nullptr.html
NULL が単に整数0を表すマクロだとは知りませんでした。
以降気をつけます！
| std::set<ListNode*> visited_nodes ; | ||
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| while (head != NULL) { | ||
| std::set<ListNode*>::iterator is_visited_it = visited_nodes.find(head) ; |
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C++11 以降では contains() を使用することをお勧めいたします。
if (visited_nodes.contains(head)) {
return true;
}
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ご指摘ありがとうございます。
ここではhead がvisited_nodes に含まれているか否かだけに関心があるのでcontains という名前のメソッドのほうが意図が伝わりますね。
以降はcontains を使いたいと思います。
https://cpprefjp.github.io/reference/set/set/contains.html
| return true; | ||
| } | ||
| visited_nodes.insert(head) ; | ||
| head = head -> next ; |
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ご指摘ありがとうございます！
そういえばメンバにアクセスする際の'.' でスペースあけるのは明らかに不自然なのですから、'->' でも空けないのが自然に感じられますね。以降気をつけます。
huyfififi
approved these changes
Jul 4, 2025
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https://leetcode.com/problems/linked-list-cycle/description/
Step3 まで完了しました。レビューのほどよろしくお願いいたします。