<p>Given an array of integers <code>arr</code>, and three integers <code>a</code>, <code>b</code> and <code>c</code>. You need to find the number of good triplets.</p> <p>A triplet <code>(arr[i], arr[j], arr[k])</code> is <strong>good</strong> if the following conditions are true:</p> <ul> <li><code>0 <= i < j < k < arr.length</code></li> <li><code>|arr[i] - arr[j]| <= a</code></li> <li><code>|arr[j] - arr[k]| <= b</code></li> <li><code>|arr[i] - arr[k]| <= c</code></li> </ul> <p>Where <code>|x|</code> denotes the absolute value of <code>x</code>.</p> <p>Return<em> the number of good triplets</em>.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3 <strong>Output:</strong> 4 <strong>Explanation:</strong> There are 4 good triplets: [(3,0,1), (3,0,1), (3,1,1), (0,1,1)]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> arr = [1,1,2,2,3], a = 0, b = 0, c = 1 <strong>Output:</strong> 0 <strong>Explanation: </strong>No triplet satisfies all conditions. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 <= arr.length <= 100</code></li> <li><code>0 <= arr[i] <= 1000</code></li> <li><code>0 <= a, b, c <= 1000</code></li> </ul>