Linked List #

• Cleverly construct a dummy head node. This can make the traversal and processing logic more uniform.
• Use recursion flexibly. By constructing recursive conditions, recursion can be used to solve problems cleverly. However, note that recursion cannot be used for some problems, because excessive recursion depth can cause timeouts and stack overflow.
• Reverse a linked list interval. Problem 92.
• Find the middle node of a linked list. Problem 876. Find the nth node from the end of a linked list. Problem 19. The answer can be obtained with just one traversal.
• Merge K sorted linked lists. Problems 21 and 23.
• Classify linked lists. Problems 86 and 328.
• Sort a linked list, requiring time complexity O(n * log n) and space complexity O(1). There is only one approach: merge sort, top-down merging. Problem 148.
• Determine whether a linked list has a cycle; if it has a cycle, output the index of the intersection point of the cycle; determine whether 2 linked lists have an intersection point; if there is an intersection point, output the intersection point. Problems 141, 142, and 160.