Improved task 64

Author: javadev

src/main/elixir/g0001_0100/s0064_minimum_path_sum/readme.md

@@ -36,20 +36,21 @@ Given a `m x n` `grid` filled with non-negative numbers, find a path from top le
 
 ```elixir
 defmodule Solution do
-    @spec min_path_sum(grid :: [[integer]]) :: integer
-    def min_path_sum(grid) do
-        traverse(grid, [0 | List.duplicate(20000, 199)])
-    end
-
-    defp traverse([], prev_row), do: Enum.at(prev_row, -1)
-    defp traverse([[first | row] | rows], [prev_row_head | prev_row]) do
-        prev_row = traverse_row(row, prev_row, [first + prev_row_head])
-        traverse(rows, prev_row)
-    end
-
-    defp traverse_row([], _prev_row, acc), do: Enum.reverse(acc)
-    defp traverse_row([head | tail], [top | prev_row], [prev | _rest] = acc) do
-        traverse_row(tail, prev_row, [head + min(prev, top) | acc])
-    end
+  @spec min_path_sum(grid :: [[integer]]) :: integer
+  def min_path_sum(grid) do
+    grid_width = length(hd(grid)) # Determine the number of columns in the grid
+    traverse(grid, [0 | List.duplicate(:infinity, grid_width - 1)])
+  end
+
+  defp traverse([], prev_row), do: Enum.at(prev_row, -1)
+  defp traverse([[first | row] | rows], [prev_row_head | prev_row]) do
+    prev_row = traverse_row(row, prev_row, [first + prev_row_head])
+    traverse(rows, prev_row)
+  end
+
+  defp traverse_row([], _prev_row, acc), do: Enum.reverse(acc)
+  defp traverse_row([head | tail], [top | prev_row], [prev | _rest] = acc) do
+    traverse_row(tail, prev_row, [head + min(prev, top) | acc])
+  end
 end
 ```