Merge pull request neetcode-gh#3366 from bgani/main

Create: 0063-unique-paths-ii.cs

Author: a93a

csharp/0063-unique-paths-ii.cs

@@ -0,0 +1,22 @@
+public class Solution {
+    public int UniquePathsWithObstacles(int[][] obstacleGrid) {
+        var rowLength = obstacleGrid.Length;
+        var colLength = obstacleGrid[0].Length;
+
+        int[] row = new int[colLength];
+        Array.Fill(row, 0);
+        row[colLength - 1] = 1;
+
+        for(int i = rowLength - 1; i >= 0; i--)
+        {
+            for(int j = colLength - 1; j >= 0; j--)
+            {
+                if(obstacleGrid[i][j] == 1)
+                    row[j] = 0;
+                else if (j + 1 < colLength) 
+                    row[j] = row[j] + row[j + 1];
+            }
+        }
+        return row[0];
+    }
+}