Key Skills About List

• Double Pointer
  • Use double or multiple pointers to loop the list
    • Examples
      • 21 Merge Two Sorted Lists
        • 1. Merge k Sorted Lists
             • Similar operation to problem 21, for the list part
             • Use priority queue (based on binary heap) to sort the K numbers
      • 86 Partition List
        • Avoid pointer cycle
  • Use double or multiple pointers to get the location of a list, one fast, one slow
    • For the close-following pointer, can consider x.Next.Next
    • When the list node number is large, no necessary to insist 1 loop
    • if there is cycle in the list
    • Examples
      • 19 Remove Nth Node from End of List
      • 876 Middle of the Linked List
        • 2095 Delete the Middle Node of a Linked List
      • 142 Linked List Cycle II
        • map or special idea
      • 160 Intersection of Two Linked Lists
        • 4 pointers. 2 faster, 2 slower
        • or use index

Reference

1. https://labuladong.github.io/algo/di-ling-zh-bfe1b/shuang-zhi-0f7cc/