Update 0062.不同路径，添加C#

problems/0062.不同路径.md

@@ -536,8 +536,29 @@ object Solution {
 ```
 
 ### c#
+```csharp
+// 二维数组
+public class Solution
+{
+    public int UniquePaths(int m, int n)
+    {
+        int[,] dp = new int[m, n];
+        for (int i = 0; i < m; i++) dp[i, 0] = 1;
+        for (int j = 0; j < n; j++) dp[0, j] = 1;
+        for (int i = 1; i < m; i++)
+        {
+            for (int j = 1; j < n; j++)
+            {
+                dp[i, j] = dp[i - 1, j] + dp[i, j - 1];
+            }
+        }
+        return dp[m - 1, n - 1];
+    }
+}
+```
 
 ```csharp
+// 一维数组
 public class Solution
 {
     public int UniquePaths(int m, int n)