## Leetcode - Remove Duplicates from Sorted List II

https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

Return the linked list sorted as well.

Example 1:

```Input: 1->2->3->3->4->4->5
Output: 1->2->5
```

Example 2:

```Input: 1->1->1->2->3
Output: 2->3
```

## Leetcode - Plus One Linked List

Given a non-negative integer represented as non-empty a singly linked list of digits, plus one to the integer.

You may assume the integer do not contain any leading zero, except the number 0 itself.

The digits are stored such that the most significant digit is at the head of the list.

Example :

```Input: [1,2,3]
Output: [1,2,4]
```

You are given a char array representing tasks CPU need to do. It contains capital letters A to Z where each letter represents a different task. Tasks could be done without the original order of the array. Each task is done in one unit of time. For each unit of time, the CPU could complete either one task or just be idle.

However, there is a non-negative integer `n` that represents the cooldown period between two same tasks (the same letter in the array), that is that there must be at least `n` units of time between any two same tasks.

You need to return the least number of units of times that the CPU will take to finish all the given tasks.

Example 1:

```Input: tasks = ["A","A","A","B","B","B"], n = 2
Output: 8
Explanation:
A -> B -> idle -> A -> B -> idle -> A -> B
There is at least 2 units of time between any two same tasks.
```

Example 2:

```Input: tasks = ["A","A","A","B","B","B"], n = 0
Output: 6
Explanation: On this case any permutation of size 6 would work since n = 0.
["A","A","A","B","B","B"]
["A","B","A","B","A","B"]
["B","B","B","A","A","A"]
...
And so on.
```

Example 3:

```Input: tasks = ["A","A","A","A","A","A","B","C","D","E","F","G"], n = 2
Output: 16
Explanation:
One possible solution is
A -> B -> C -> A -> D -> E -> A -> F -> G -> A -> idle -> idle -> A -> idle -> idle -> A
```

Constraints:

• The number of tasks is in the range `[1, 10000]`.
• The integer `n` is in the range `[0, 100]`.

## Leetcode - Top K Frequent Elements

https://leetcode.com/problems/top-k-frequent-elements/

Given a non-empty array of integers, return the k most frequent elements.

Example 1:

```Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]
```

Example 2:

```Input: nums = [1], k = 1
Output: [1]```

## Leetcode - Meeting Rooms II

https://leetcode.com/problems/meeting-rooms-ii/

Given an array of meeting time intervals consisting of start and end times `[[s1,e1],[s2,e2],...]` (si < ei), find the minimum number of conference rooms required.

Example 1:

```Input: `[[0, 30],[5, 10],[15, 20]]`
Output: 2```

Example 2:

```Input: [[7,10],[2,4]]
Output: 1```

## Leetcode - Median of Two Sorted Arrays

https://leetcode.com/problems/median-of-two-sorted-arrays/

There are two sorted arrays nums1 and nums2 of size m and n respectively.

Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

You may assume nums1 and nums2 cannot be both empty.

Example 1:

```nums1 = [1, 3]
nums2 = [2]

The median is 2.0
```