Day i do not know

994. Rotting Oranges/Solution.cs

@@ -0,0 +1,60 @@
+namespace _994._Rotting_Oranges;
+
+public class Solution
+{
+    public int OrangesRotting(int[][] mat)
+    {
+        int w = mat[0].Length;
+        int h = mat.Length;
+
+        Work(mat, i =>
+        {
+            int y = h - i / w - 1;
+            int x = i % w;
+            return (y, x);
+        });
+        Work(mat, i =>
+        {
+            int y = i / w;
+            int x = w - i % w - 1;
+            return (y, x);
+        });
+        Work(mat, i =>
+        {
+            int y = i / w;
+            int x = i % w;
+            return (y, x);
+        });
+        int max = Work(mat, i =>
+        {
+            int y = h - i / w - 1;
+            int x = w - i % w - 1;
+            return (y, x);
+        });
+        return max;
+    }
+
+    private int Work(int[][] mat, Func<int, (int y, int x)> getXY)
+    {
+        int absMax = 0;
+        for (int i = 0; i < mat.Length * mat[0].Length; i++)
+        {
+            var dot = getXY(i);
+            int x = dot.x;
+            int y = dot.y;
+            if (mat[y][x] == 0)
+                continue;
+            int max = int.MinValue;
+            for (int shift = 1; shift < 9; shift += 2)
+            {
+                int newY = shift / 3 + y - 1;
+                int newX = shift % 3 + x - 1;
+                if (newY >= 0 && newY < mat.Length && newX >= 0 && newX < mat[newY].Length)
+                    max = Math.Max(max, mat[newY][newX]);
+            }
+            mat[y][x] = max + 1;
+            absMax = Math.Max(absMax, mat[y][x]);
+        }
+        return absMax;
+    }
+}