Add solution #3318

Author: JoshCrozier

README.md

@@ -2703,6 +2703,7 @@
 3306|[Count of Substrings Containing Every Vowel and K Consonants II](./solutions/3306-count-of-substrings-containing-every-vowel-and-k-consonants-ii.js)|Medium|
 3307|[Find the K-th Character in String Game II](./solutions/3307-find-the-k-th-character-in-string-game-ii.js)|Hard|
 3313|[Find the Last Marked Nodes in Tree](./solutions/3313-find-the-last-marked-nodes-in-tree.js)|Hard|
+3318|[Find X-Sum of All K-Long Subarrays I](./solutions/3318-find-x-sum-of-all-k-long-subarrays-i.js)|Easy|
 3323|[Minimize Connected Groups by Inserting Interval](./solutions/3323-minimize-connected-groups-by-inserting-interval.js)|Medium|
 3329|[Count Substrings With K-Frequency Characters II](./solutions/3329-count-substrings-with-k-frequency-characters-ii.js)|Hard|
 3330|[Find the Original Typed String I](./solutions/3330-find-the-original-typed-string-i.js)|Easy|

solutions/3318-find-x-sum-of-all-k-long-subarrays-i.js

@@ -0,0 +1,60 @@
+/**
+ * 3318. Find X-Sum of All K-Long Subarrays I
+ * https://leetcode.com/problems/find-x-sum-of-all-k-long-subarrays-i/
+ * Difficulty: Easy
+ *
+ * You are given an array nums of n integers and two integers k and x.
+ *
+ * The x-sum of an array is calculated by the following procedure:
+ * - Count the occurrences of all elements in the array.
+ * - Keep only the occurrences of the top x most frequent elements. If two elements
+ *   have the same number of occurrences, the element with the bigger value is
+ *   considered more frequent.
+ * - Calculate the sum of the resulting array.
+ *
+ * Note that if an array has less than x distinct elements, its x-sum is the sum of the array.
+ *
+ Return an integer array answer of length n - k + 1 where answer[i] is the x-sum of the
+ subarray nums[i..i + k - 1].
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @param {number} x
+ * @return {number[]}
+ */
+var findXSum = function(nums, k, x) {
+  const n = nums.length;
+  const result = [];
+
+  for (let i = 0; i <= n - k; i++) {
+    const subarray = nums.slice(i, i + k);
+    result.push(helper(subarray));
+  }
+
+  return result;
+
+  function helper(subarray) {
+    const frequency = new Map();
+
+    for (const num of subarray) {
+      frequency.set(num, (frequency.get(num) || 0) + 1);
+    }
+
+    const elements = Array.from(frequency.entries());
+    elements.sort((a, b) => {
+      if (a[1] !== b[1]) return b[1] - a[1];
+      return b[0] - a[0];
+    });
+
+    const topX = elements.slice(0, x);
+    let sum = 0;
+
+    for (const [value, count] of topX) {
+      sum += value * count;
+    }
+
+    return sum;
+  }
+};