Solve 9th July problem

Author: SartHak-0-Sach

191-9th_July-Average_waiting_time/approach-explanation.txt

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+Intuition
+To solve the problem of calculating the average waiting time for customers in a restaurant, we use a simple iterative approach. The key steps involve simulating the process of serving each customer and calculating the total waiting time.
+
+Approach
+Input Handling:
+
+customers is a 2D array where each element is an array representing a customer's arrival time and cooking time.
+Initialization:
+
+N stores the number of customers.
+serviceTime is initialized to the sum of the arrival time and cooking time of the first customer.
+totalWait is initialized to the waiting time of the first customer.
+Loop Through Customers:
+
+For each customer from the second one onwards:
+Check if the chef needs to wait for the customer to arrive.
+Update serviceTime to include the cooking time of the current customer.
+Calculate the waiting time for the current customer and add it to totalWait.
+Calculate and Return Average:
+
+Divide totalWait by N to get the average waiting time.
+Complexity
+Time complexity: O(N) [N = Row size]
+Space complexity: 0(1)

191-9th_July-Average_waiting_time/code.cpp

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+class Solution
+{
+public:
+    double averageWaitingTime(vector<vector<int>> &customers)
+    {
+        int N = customers.size();
+        double serviceTime = customers[0][0] + customers[0][1];
+        double totalWait = serviceTime - customers[0][0];
+
+        for (int i = 1; i < N; i++)
+        {
+            if (serviceTime < customers[i][0])
+                serviceTime = customers[i][0];
+            serviceTime += customers[i][1];
+            totalWait += (serviceTime - customers[i][0]);
+        }
+        return totalWait / N;
+    }
+};