Add solution #1755

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,522 LeetCode solutions in JavaScript
+# 1,523 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1352,6 +1352,7 @@
 1752|[Check if Array Is Sorted and Rotated](./solutions/1752-check-if-array-is-sorted-and-rotated.js)|Easy|
 1753|[Maximum Score From Removing Stones](./solutions/1753-maximum-score-from-removing-stones.js)|Medium|
 1754|[Largest Merge Of Two Strings](./solutions/1754-largest-merge-of-two-strings.js)|Medium|
+1755|[Closest Subsequence Sum](./solutions/1755-closest-subsequence-sum.js)|Hard|
 1764|[Form Array by Concatenating Subarrays of Another Array](./solutions/1764-form-array-by-concatenating-subarrays-of-another-array.js)|Medium|
 1765|[Map of Highest Peak](./solutions/1765-map-of-highest-peak.js)|Medium|
 1768|[Merge Strings Alternately](./solutions/1768-merge-strings-alternately.js)|Easy|

solutions/1755-closest-subsequence-sum.js

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+/**
+ * 1755. Closest Subsequence Sum
+ * https://leetcode.com/problems/closest-subsequence-sum/
+ * Difficulty: Hard
+ *
+ * You are given an integer array nums and an integer goal.
+ *
+ * You want to choose a subsequence of nums such that the sum of its elements is the closest
+ * possible to goal. That is, if the sum of the subsequence's elements is sum, then you want
+ * to minimize the absolute difference abs(sum - goal).
+ *
+ * Return the minimum possible value of abs(sum - goal).
+ *
+ * Note that a subsequence of an array is an array formed by removing some elements (possibly
+ * all or none) of the original array.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number} goal
+ * @return {number}
+ */
+var minAbsDifference = function(nums, goal) {
+  const n = nums.length;
+  const half = Math.floor(n / 2);
+  const leftSums = new Set();
+  const rightSums = new Set();
+
+  generateSums(0, half, leftSums);
+  generateSums(half, n, rightSums);
+
+  const rightArray = [...rightSums].sort((a, b) => a - b);
+  let minDiff = Infinity;
+
+  for (const leftSum of leftSums) {
+    const target = goal - leftSum;
+    let left = 0;
+    let right = rightArray.length - 1;
+
+    while (left <= right) {
+      const mid = Math.floor((left + right) / 2);
+      const sum = leftSum + rightArray[mid];
+      minDiff = Math.min(minDiff, Math.abs(sum - goal));
+
+      if (sum < goal) {
+        left = mid + 1;
+      } else {
+        right = mid - 1;
+      }
+    }
+  }
+
+  return minDiff;
+
+  function generateSums(start, end, sums, current = 0) {
+    if (start === end) {
+      sums.add(current);
+      return;
+    }
+    generateSums(start + 1, end, sums, current);
+    generateSums(start + 1, end, sums, current + nums[start]);
+  }
+};