# 1534. Count Good Triplets

https://leetcode.com/problems/count-good-triplets

## Description

Given an array of integers `arr`, and three integers `a`, `b` and `c`. You need to find the number of good triplets.

A triplet `(arr[i], arr[j], arr[k])` is **good** if the following conditions are true:

* `0 <= i < j < k < arr.length`
* `|arr[i] - arr[j]| <= a`
* `|arr[j] - arr[k]| <= b`
* `|arr[i] - arr[k]| <= c`

Where `|x|` denotes the absolute value of `x`.

Return _the number of good triplets_.

**Example 1:**

```

**Input:** arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3
**Output:** 4
**Explanation:** There are 4 good triplets: [(3,0,1), (3,0,1), (3,1,1), (0,1,1)].
```

**Example 2:**

```

**Input:** arr = [1,1,2,2,3], a = 0, b = 0, c = 1
**Output:** 0
**Explanation:** No triplet satisfies all conditions.
```

**Constraints:**

* `3 <= arr.length <= 100`
* `0 <= arr[i] <= 1000`
* `0 <= a, b, c <= 1000`

## ac

```java
```
