# Unique Occurrences

Given a list of integers `nums`

, return whether the **number of occurrences** of every value in the array is unique.

Note: Numbers can be negative.

**Constraints**

`0 ≤ n ≤ 100,000`

where`n`

is the length of`nums`

https://binarysearch.com/problems/Unique-Occurrences

## Examples

### Example 1

**Input**

- nums =
`[-3, -1, -1, -1, -2, -2]`

**Output**

- answer =
`True`

**Explanation**

There’s 1 occurrence of -3, 2 occurrences of -2, and 3 occurrences of -1. All number of occurrences are unique.

### Example 2

**Input**

- nums =
`[3, 1, 1, 2, 2, 2, 3]`

**Output**

- answer =
`False`

**Explanation**

There are 2 occurrences of 1, and 2 occurrences of 3. So the number of occurrences here is not unique.

### Example 3

**Input**

- nums =
`[5, 3, 1, 8, 3, 1, 1, 8, 8, 8]`

**Output**

- answer =
`True`

**Explanation**

There’s 1 occurrence of 5, 2 occurrences of 3, 3 occurrences of 1, and 4 occurrences of 8. All number of occurrences are unique.

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