Create average-waiting-time.cpp

Author: kamyu104

C++/average-waiting-time.cpp

@@ -0,0 +1,14 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    double averageWaitingTime(vector<vector<int>>& customers) {
+        double avai = 0, wait = 0;
+        for (const auto& c : customers) {
+            avai = max(avai, double(c[0])) + c[1];
+            wait += avai - c[0];
+        }
+        return wait / size(customers);
+    }
+};