Update 0377.组合综合4，添加C#

problems/0377.组合总和Ⅳ.md

@@ -312,6 +312,28 @@ impl Solution {
     }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public int CombinationSum4(int[] nums, int target)
+    {
+        int[] dp = new int[target + 1];
+        dp[0] = 1;
+        for (int i = 0; i <= target; i++)
+        {
+            for (int j = 0; j < nums.Length; j++)
+            {
+                if (i >= nums[j] && dp[i] < int.MaxValue - dp[i - nums[j]])
+                {
+                    dp[i] += dp[i - nums[j]];
+                }
+            }
+        }
+        return dp[target];
+    }
+}
+```
 
 
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