Update previous work LeetCode75

Author: Adam Lin

643_findMaxAverage.cpp

@@ -0,0 +1,31 @@
+class Solution {
+public:
+    double findMaxAverage(vector<int>& nums, int k) {
+        int s = 0;
+        double avg = 0;
+        double sum = 0;
+        vector<double> result;
+
+        for(int i = 0; i < nums.size(); i++){
+            sum += nums[i];
+
+            // when i met index k means i is in the end of the window
+            // so calculate the avg 
+            if(i >= k - 1){
+                avg = sum / k;
+                result.push_back(avg);
+                
+                // Substrate the first of value in window
+                sum -= nums[s];
+                // move the start value to next
+                s++;
+            }
+            
+        }
+
+        // max_element returns an iterator pointing to the largest element in the container
+        //(e.g., a std::vector), not the value itself.
+        // * is used to access the value pointed to by a pointer or an iterator
+        return *max_element(result.begin(), result.end());
+    }
+};