1882\. Process Tasks Using Servers

Medium

You are given two **0-indexed** integer arrays `servers` and `tasks` of lengths `n` and `m` respectively. `servers[i]` is the **weight** of the <code>i<sup>th</sup></code> server, and `tasks[j]` is the **time needed** to process the <code>j<sup>th</sup></code> task **in seconds**.

Tasks are assigned to the servers using a **task queue**. Initially, all servers are free, and the queue is **empty**.

At second `j`, the <code>j<sup>th</sup></code> task is **inserted** into the queue (starting with the <code>0<sup>th</sup></code> task being inserted at second `0`). As long as there are free servers and the queue is not empty, the task in the front of the queue will be assigned to a free server with the **smallest weight**, and in case of a tie, it is assigned to a free server with the **smallest index**.

If there are no free servers and the queue is not empty, we wait until a server becomes free and immediately assign the next task. If multiple servers become free at the same time, then multiple tasks from the queue will be assigned **in order of insertion** following the weight and index priorities above.

A server that is assigned task `j` at second `t` will be free again at second `t + tasks[j]`.

Build an array `ans` of length `m`, where `ans[j]` is the **index** of the server the <code>j<sup>th</sup></code> task will be assigned to.

Return _the array_ `ans`.

**Example 1:**

**Input:** servers = [3,3,2], tasks = [1,2,3,2,1,2]

**Output:** [2,2,0,2,1,2]

**Explanation:** Events in chronological order go as follows:

- At second 0, task 0 is added and processed using server 2 until second 1.

- At second 1, server 2 becomes free. Task 1 is added and processed using server 2 until second 3.

- At second 2, task 2 is added and processed using server 0 until second 5.

- At second 3, server 2 becomes free. Task 3 is added and processed using server 2 until second 5.

- At second 4, task 4 is added and processed using server 1 until second 5.

- At second 5, all servers become free. Task 5 is added and processed using server 2 until second 7.

**Example 2:**

**Input:** servers = [5,1,4,3,2], tasks = [2,1,2,4,5,2,1]

**Output:** [1,4,1,4,1,3,2]

**Explanation:** Events in chronological order go as follows:

- At second 0, task 0 is added and processed using server 1 until second 2.

- At second 1, task 1 is added and processed using server 4 until second 2.

- At second 2, servers 1 and 4 become free. Task 2 is added and processed using server 1 until second 4.

- At second 3, task 3 is added and processed using server 4 until second 7.

- At second 4, server 1 becomes free. Task 4 is added and processed using server 1 until second 9.

- At second 5, task 5 is added and processed using server 3 until second 7.

- At second 6, task 6 is added and processed using server 2 until second 7. 

**Constraints:**

*   `servers.length == n`
*   `tasks.length == m`
*   <code>1 <= n, m <= 2 * 10<sup>5</sup></code>
*   <code>1 <= servers[i], tasks[j] <= 2 * 10<sup>5</sup></code>