Reverse String Solution for Cognizant
Company: Cognizant · Difficulty: Easy · Topics: String, Two Pointers
Problem Statement
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.
Examples
Example 1:
Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
Example 2:
Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]
Approach
Use two pointers (left and right) to swap characters from both ends, moving towards the center.
Time and Space Complexity
- Time Complexity: O(n)
- Space Complexity: O(1)