added reverse string

Author: clfhhc

problems/0344-reverse-string.ts

@@ -0,0 +1,94 @@
+/**
+ * 0344. Reverse String
+ *
+ * Difficulty: easy
+ * Tags: two-pointers, string
+ *
+ * Description:
+ * Write a function that reverses a string. The input string is given as an array of characters `s`.
+ *
+ * You must do this by modifying the input array [in-place](https://en.wikipedia.org/wiki/In-place_algorithm) with `O(1)` extra memory.
+ *
+ * Examples:
+ * 1. Input: s = \["h","e","l","l","o"\]
+ *    Output: \["o","l","l","e","h"\]
+ * 2. Input: s = \["H","a","n","n","a","h"\]
+ *    Output: \["h","a","n","n","a","H"\]
+ *
+ * Constraints:
+ * - `1 <= s.length <= 10^5`
+ * - `s[i]` is a [printable ascii character](https://en.wikipedia.org/wiki/ASCII#Printable_characters).
+ *
+ */
+import { z } from 'zod';
+import type { TestCase } from '../packages/src/types.js';
+
+export const SolutionSchema = z.function({
+  input: [z.array(z.string().length(1))],
+  output: z.array(z.string().length(1)),
+});
+
+export type Solution = z.infer<typeof SolutionSchema>;
+
+export const cases: TestCase<Solution>[] = [
+  {
+    input: [['h', 'e', 'l', 'l', 'o']],
+    expected: ['o', 'l', 'l', 'e', 'h'],
+    name: 'Example 1',
+  },
+  {
+    input: [['H', 'a', 'n', 'n', 'a', 'h']],
+    expected: ['h', 'a', 'n', 'n', 'a', 'H'],
+    name: 'Example 2',
+  },
+];
+
+/**
+ * Recursive Solution
+ * Approach:
+ *   - Use a recursive function to reverse the array
+ *   - Return the reversed array
+ * Time Complexity: O(n)
+ * Space Complexity: O(n)
+ */
+export const recursiveSolution = SolutionSchema.implement((s) => {
+  if (s.length <= 1) {
+    return s;
+  }
+  const helper = (left: number, right: number) => {
+    if (left >= right) {
+      return;
+    }
+    [s[left], s[right]] = [s[right], s[left]];
+    helper(left + 1, right - 1);
+  };
+  helper(0, s.length - 1);
+  return s;
+});
+
+/**
+ * Iterative Solution
+ * Approach:
+ *   - Use a while loop to reverse the array
+ *   - Return the reversed array
+ * Time Complexity: O(n)
+ * Space Complexity: O(1)
+ */
+export const iterativeSolution = SolutionSchema.implement((s) => {
+  if (s.length <= 1) {
+    return s;
+  }
+  let left = 0;
+  let right = s.length - 1;
+  let temp: string;
+  while (left < right) {
+    temp = s[left];
+    s[left] = s[right];
+    s[right] = temp;
+    left++;
+    right--;
+  }
+  return s;
+});
+
+export const solutions = [recursiveSolution, iterativeSolution];