g0001_0100.s0062_unique_paths.Solution.ex Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-all Show documentation

104 LeetCode algorithm problem solutions

There is a newer version: 1.8

# #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Dynamic_Programming #Math
# #Combinatorics #Algorithm_II_Day_13_Dynamic_Programming #Dynamic_Programming_I_Day_15
# #Level_1_Day_11_Dynamic_Programming #Big_O_Time_O(m*n)_Space_O(m*n)
# #2024_08_02_Time_233_ms_(100.00%)_Space_71.9_MB_(66.67%)

defmodule Solution do
  @spec unique_paths(m :: integer, n :: integer) :: integer
  def unique_paths(m, n) do
    ncr(m + n - 2, min(m, n) - 1)
  end

  defp ncr(n, r) do
    Enum.reduce(1..r#1, 1, fn i, acc ->
      div(acc * (i + n - r), i)
    end)
  end
end