https://leetcode.com/problems/reverse-string/

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"]

class Solution:
    def reverseString(self, s: List[str]) -> None:
        l, r = 0, len(s)-1
        while r > l:
            s[l], s[r] = s[r], s[l]
            r -= 1
            l += 1

• Algo

func reverseString(s []byte) {
	i := 0
	j := len(s) - 1

	for i < j {
		left := s[i]
		s[i] = s[j]
		s[j] = left

		i++
		j--
	}
}