Add solution #848

Author: JoshCrozier

README.md

@@ -655,6 +655,7 @@
 845|[Longest Mountain in Array](./0845-longest-mountain-in-array.js)|Medium|
 846|[Hand of Straights](./0846-hand-of-straights.js)|Medium|
 847|[Shortest Path Visiting All Nodes](./0847-shortest-path-visiting-all-nodes.js)|Hard|
+848|[Shifting Letters](./0848-shifting-letters.js)|Medium|
 867|[Transpose Matrix](./0867-transpose-matrix.js)|Easy|
 868|[Binary Gap](./0868-binary-gap.js)|Easy|
 872|[Leaf-Similar Trees](./0872-leaf-similar-trees.js)|Easy|

solutions/0848-shifting-letters.js

@@ -0,0 +1,40 @@
+/**
+ * 848. Shifting Letters
+ * https://leetcode.com/problems/shifting-letters/
+ * Difficulty: Medium
+ *
+ * You are given a string s of lowercase English letters and an integer array shifts of the
+ * same length.
+ *
+ * Call the shift() of a letter, the next letter in the alphabet, (wrapping around so that
+ * 'z' becomes 'a').
+ *
+ * For example, shift('a') = 'b', shift('t') = 'u', and shift('z') = 'a'.
+ *
+ * Now for each shifts[i] = x, we want to shift the first i + 1 letters of s, x times.
+ *
+ * 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 cumulativeShifts = new Array(s.length).fill(0);
+
+  cumulativeShifts[s.length - 1] = shifts[s.length - 1] % 26;
+  for (let i = s.length - 2; i >= 0; i--) {
+    cumulativeShifts[i] = (cumulativeShifts[i + 1] + shifts[i]) % 26;
+  }
+
+  let result = '';
+  for (let i = 0; i < s.length; i++) {
+    const charCode = s.charCodeAt(i);
+    const shiftedCode = ((charCode - 97 + cumulativeShifts[i]) % 26) + 97;
+    result += String.fromCharCode(shiftedCode);
+  }
+
+  return result;
+};