1: fast and slow pointer and double pointer

Fast and slow Pointers with binary search

1.1: Application scenarios of fast and slow Pointers

  • Check whether the list has rings
  • Return the starting position of a linked list containing rings
  • Find the midpoint of the list
  • Find the penultimate KTH element of the list

1.2: Usage scenario of left and right Pointers

  • Binary search
  • Sum of two numbers (array ordered)
  • Inversion array
  • The sliding window