Reverse String — Easy Coding Interview Question

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 with O(1) extra memory.

Example

Input: s = ["h","e","l","l","o"]

Output: ["o","l","l","e","h"]

Constraints

• 1 ≤ s.length ≤ 10⁵
• s[i] is a printable ASCII character

Topics & Companies

Topics: strings, two-pointers

Asked by: Amazon, Google, Meta, Microsoft, Apple

Optimal Solution Complexity

Time complexity: O(n). Space complexity: O(1).

Practice more

• All DSA Problems
• DSA Patterns