Add solution #2381

Author: JoshCrozier

README.md

@@ -559,6 +559,7 @@
 2352|[Equal Row and Column Pairs](./2352-equal-row-and-column-pairs.js)|Medium|
 2364|[Count Number of Bad Pairs](./2364-count-number-of-bad-pairs.js)|Medium|
 2375|[Construct Smallest Number From DI String](./2375-construct-smallest-number-from-di-string.js)|Medium|
+2381|[Shifting Letters II](./2381-shifting-letters-ii.js)|Medium|
 2390|[Removing Stars From a String](./2390-removing-stars-from-a-string.js)|Medium|
 2396|[Strictly Palindromic Number](./2396-strictly-palindromic-number.js)|Medium|
 2413|[Smallest Even Multiple](./2413-smallest-even-multiple.js)|Easy|

solutions/2381-shifting-letters-ii.js

@@ -0,0 +1,38 @@
+/**
+ * 2381. Shifting Letters II
+ * https://leetcode.com/problems/shifting-letters-ii/
+ * Difficulty: Medium
+ *
+ * You are given a string s of lowercase English letters and a 2D integer array shifts where
+ * shifts[i] = [starti, endi, directioni]. For every i, shift the characters in s from the
+ * index starti to the index endi (inclusive) forward if directioni = 1, or shift the characters
+ * backward if directioni = 0.
+ *
+ * Shifting a character forward means replacing it with the next letter in the alphabet (wrapping
+ * around so that 'z' becomes 'a'). Similarly, shifting a character backward means replacing it
+ * with the previous letter in the alphabet (wrapping around so that 'a' becomes 'z').
+ *
+ * Return the final string after all such shifts to s are applied.
+ */
+
+/**
+ * @param {string} s
+ * @param {number[][]} shifts
+ * @return {string}
+ */
+var shiftingLetters = function(s, shifts) {
+  const compare = new Array(s.length).fill(0);
+  for (const [start, end, direction] of shifts) {
+    compare[start] += direction === 1 ? 1 : -1;
+    if (end + 1 < s.length) {
+      compare[end + 1] += direction === 1 ? -1 : 1;
+    }
+  }
+  let result = '';
+  for (let i = 0, count = 0; i < s.length; i++) {
+    count = (count + compare[i]) % 26;
+    count = count < 0 ? count + 26 : count;
+    result += String.fromCharCode((s.charCodeAt(i) - 97 + count) % 26 + 97);
+  }
+  return result;
+};