Add solution #532

Author: JoshCrozier

README.md

@@ -426,6 +426,7 @@
 528|[Random Pick with Weight](./0528-random-pick-with-weight.js)|Medium|
 529|[Minesweeper](./0529-minesweeper.js)|Medium|
 530|[Minimum Absolute Difference in BST](./0530-minimum-absolute-difference-in-bst.js)|Easy|
+532|[K-diff Pairs in an Array](./0532-k-diff-pairs-in-an-array.js)|Medium|
 541|[Reverse String II](./0541-reverse-string-ii.js)|Easy|
 542|[01 Matrix](./0542-01-matrix.js)|Medium|
 543|[Diameter of Binary Tree](./0543-diameter-of-binary-tree.js)|Easy|

solutions/0532-k-diff-pairs-in-an-array.js

@@ -0,0 +1,42 @@
+/**
+ * 532. K-diff Pairs in an Array
+ * https://leetcode.com/problems/k-diff-pairs-in-an-array/
+ * Difficulty: Medium
+ *
+ * Given an array of integers nums and an integer k, return the number of unique k-diff
+ * pairs in the array.
+ *
+ * A k-diff pair is an integer pair (nums[i], nums[j]), where the following are true:
+ * - 0 <= i, j < nums.length
+ * - i != j
+ * - |nums[i] - nums[j]| == k
+ *
+ * Notice that |val| denotes the absolute value of val.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+var findPairs = function(nums, k) {
+  const map = new Map();
+  let result = 0;
+
+  for (const num of nums) {
+    if (!map.has(num)) {
+      if (!k) {
+        map.set(num, 1);
+      } else {
+        if (map.has(num - k)) result++;
+        if (map.has(num + k)) result++;
+        map.set(num, 1);
+      }
+    } else if (!k && map.get(num) === 1) {
+      result++;
+      map.set(num, 2);
+    }
+  }
+
+  return result;
+};