# Question

You’re given a non-empty array of positive integers representing the amount of time that specific queries take to execute. Only one query can be executed at a time, but the queries can be executed in any order.

A query’s waiting time is defined as the amount of time that it must wait before its execution starts. In other words, if a query is executed second, then its waiting time is the duration of the first query; if a query is executed third, then its waiting time is the sum of the duration of the first two queries.

Write a function that returns the minimum amount of total waiting time for all of the queries. For example, if you’re given the queries of durations [1, 4, 5], then the total waiting time if the queries were executed in the order of [5, 1, 4] would be (0) +(5) + (5 + 1) = 11. The first query of duration 5 would be executed immediately, so its waiting time would be 0, the second query of duration 1 would have to wait 5 seconds (the duration of the first query) to be executed, and the last query would have to wait for the duration of the first two queries before being executed.

Note: you’re allowed to mutate the input array.

# Sample Input:

queries = [3, 2, 1, 2, 6]

17

# Solution

`private int MinWaitingTime(int[] queries){            // Time Complexity - O(n logn)            // Space Complexity - O(1)            Array.Sort(queries);            int sum = 0;            int waitingTime = 0;            // Waiting time of first query is always 0            for (int i = 0; i < queries.Length - 1; i++)            {                waitingTime += queries[i];                sum += waitingTime;            }            return sum;}`

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