Add solution #719

Author: JoshCrozier

README.md

@@ -543,6 +543,7 @@
 715|[Range Module](./0715-range-module.js)|Hard|
 717|[1-bit and 2-bit Characters](./0717-1-bit-and-2-bit-characters.js)|Easy|
 718|[Maximum Length of Repeated Subarray](./0718-maximum-length-of-repeated-subarray.js)|Medium|
+719|[Find K-th Smallest Pair Distance](./0719-find-k-th-smallest-pair-distance.js)|Hard|
 720|[Longest Word in Dictionary](./0720-longest-word-in-dictionary.js)|Medium|
 722|[Remove Comments](./0722-remove-comments.js)|Medium|
 724|[Find Pivot Index](./0724-find-pivot-index.js)|Easy|

solutions/0719-find-k-th-smallest-pair-distance.js

@@ -0,0 +1,40 @@
+/**
+ * 719. Find K-th Smallest Pair Distance
+ * https://leetcode.com/problems/find-k-th-smallest-pair-distance/
+ * Difficulty: Hard
+ *
+ * The distance of a pair of integers a and b is defined as the absolute difference between a and b.
+ *
+ * Given an integer array nums and an integer k, return the kth smallest distance among all the
+ * pairs nums[i] and nums[j] where 0 <= i < j < nums.length.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+var smallestDistancePair = function(nums, k) {
+  nums.sort((a, b) => a - b);
+  let left = 0;
+  let right = nums[nums.length - 1] - nums[0];
+
+  while (left < right) {
+    const middle = Math.floor((left + right) / 2);
+    let count = 0;
+    let j = 0;
+
+    for (let i = 0; i < nums.length; i++) {
+      while (j < nums.length && nums[j] - nums[i] <= middle) j++;
+      count += j - i - 1;
+    }
+
+    if (count < k) {
+      left = middle + 1;
+    } else {
+      right = middle;
+    }
+  }
+
+  return left;
+};