diff --git a/LeetCode-CN/643.cpp b/LeetCode-CN/643.cpp
new file mode 100644
index 0000000..763b229
--- /dev/null
+++ b/LeetCode-CN/643.cpp
@@ -0,0 +1,22 @@
+class Solution {
+public:
+	double findMaxAverage(vector<int>& nums, int k) {
+		int n = nums.size();
+		int sum = 0;
+		for (int i = 0; i < k; i++)
+		{
+			sum += nums[i];
+		}
+		int current = sum;
+		int max = current;
+		for (int begin = 1; begin + k <= n; begin++)
+		{
+			current = current - nums[begin - 1] + nums[begin + k - 1];
+			if (current > max)
+			{
+				max = current;
+			}
+		}
+		return (double)max / k;
+	}
+};