Solution 84: Pairs of Lattice Paths with Restrictions

  • Published on Mar 21, 2019
  • Let's perform careful casework to formulate a recursive argument: How did the paths look like one step before?
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Comments • 6

  • Sahil Baori
    Sahil Baori 6 months ago

    Can A and B go back and retrace their paths?

    • LetsSolveMathProblems
      LetsSolveMathProblems  6 months ago

      In some sense, we are retracing the paths of A and B to establish the recurrence in the video. More precisely, to find the relationship between the number of pairs of A and B of length n and the number of pairs of A and B of length n-1, we are considering what should have happened at the final step of A and B AND how A and B should have looked like immediately before the final step in order to get the desired paths at the end.

  • Sweety XS
    Sweety XS 6 months ago +2

    Btw how much educated should we be to answer or understand this solution??

    • Sweety XS
      Sweety XS 6 months ago +1

      @Aaron He me too

    • Aaron He
      Aaron He 6 months ago +3

      Probably a decent knowledge of recursive functions, which I don't have lol.

  • Jeremy Weissmann
    Jeremy Weissmann 6 months ago +3

    I may not have been the first to answer but it was nice to see you cover an approach similar to the one I used in this video!