Add solution #1679

Author: JoshCrozier

README.md

@@ -351,6 +351,7 @@
 1668|[Maximum Repeating Substring](./1668-maximum-repeating-substring.js)|Easy|
 1669|[Merge In Between Linked Lists](./1669-merge-in-between-linked-lists.js)|Medium|
 1672|[Richest Customer Wealth](./1672-richest-customer-wealth.js)|Easy|
+1679|[Max Number of K-Sum Pairs](./1679-max-number-of-k-sum-pairs.js)|Medium|
 1716|[Calculate Money in Leetcode Bank](./1716-calculate-money-in-leetcode-bank.js)|Easy|
 1748|[Sum of Unique Elements](./1748-sum-of-unique-elements.js)|Easy|
 1768|[Merge Strings Alternately](./1768-merge-strings-alternately.js)|Easy|

solutions/1679-max-number-of-k-sum-pairs.js

@@ -0,0 +1,35 @@
+/**
+ * 1679. Max Number of K-Sum Pairs
+ * https://leetcode.com/problems/max-number-of-k-sum-pairs/
+ * Difficulty: Medium
+ *
+ * You are given an integer array nums and an integer k.
+ *
+ * In one operation, you can pick two numbers from the array whose sum equals k and
+ * remove them from the array.
+ *
+ * Return the maximum number of operations you can perform on the array.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+var maxOperations = function(nums, k) {
+  const map = new Map();
+  let result = 0;
+
+  nums.forEach(n => {
+    const diff = k - n;
+
+    if (map.get(diff)) {
+      result++;
+      map.set(diff, map.get(diff) - 1);
+    } else {
+      map.set(n, (map.get(n) ?? 0) + 1);
+    }
+  });
+
+  return result;
+};