feat: add cs solution to lc problem: No.1630

solution/1600-1699/1630.Arithmetic Subarrays/README.md

@@ -254,6 +254,36 @@ impl Solution {
 }
 ```
 
+### **C#**
+
+```cs
+class Solution {
+    public bool Check(int[] arr) {
+        Array.Sort(arr);
+        int diff = arr[1] - arr[0];
+        for (int i = 2; i < arr.Length; i++) {
+            if (arr[i] - arr[i - 1] != diff) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public IList<bool> CheckArithmeticSubarrays(int[] nums, int[] l, int[] r) {
+        List<bool> ans = new List<bool>();
+        for (int i = 0; i < l.Length; i++) {
+            int[] arr = new int[r[i] - l[i] + 1];
+            for (int j = 0; j < arr.Length; j++) {
+                arr[j] = nums[l[i] + j];
+            }
+            ans.Add(Check(arr));
+        }
+        return ans;
+    }
+}
+
+```
+
 ### **...**
 
 ```

solution/1600-1699/1630.Arithmetic Subarrays/README_EN.md

@@ -234,6 +234,36 @@ impl Solution {
 }
 ```
 
+### **C#**
+
+```cs
+class Solution {
+    public bool Check(int[] arr) {
+        Array.Sort(arr);
+        int diff = arr[1] - arr[0];
+        for (int i = 2; i < arr.Length; i++) {
+            if (arr[i] - arr[i - 1] != diff) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public IList<bool> CheckArithmeticSubarrays(int[] nums, int[] l, int[] r) {
+        List<bool> ans = new List<bool>();
+        for (int i = 0; i < l.Length; i++) {
+            int[] arr = new int[r[i] - l[i] + 1];
+            for (int j = 0; j < arr.Length; j++) {
+                arr[j] = nums[l[i] + j];
+            }
+            ans.Add(Check(arr));
+        }
+        return ans;
+    }
+}
+
+```
+
 ### **...**
 
 ```

solution/1600-1699/1630.Arithmetic Subarrays/Solution.cs

@@ -0,0 +1,24 @@
+class Solution {
+    public bool Check(int[] arr) {
+        Array.Sort(arr);
+        int diff = arr[1] - arr[0];
+        for (int i = 2; i < arr.Length; i++) {
+            if (arr[i] - arr[i - 1] != diff) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public IList<bool> CheckArithmeticSubarrays(int[] nums, int[] l, int[] r) {
+        List<bool> ans = new List<bool>();
+        for (int i = 0; i < l.Length; i++) {
+            int[] arr = new int[r[i] - l[i] + 1];
+            for (int j = 0; j < arr.Length; j++) {
+                arr[j] = nums[l[i] + j];
+            }
+            ans.Add(Check(arr));
+        }
+        return ans;
+    }
+}