#541

Reverse String II

easy · verified · 53.4% accepted · 2,342 likes · top 44%

two pointers · string

⊣ practice⊣ quiz⊣ open on leetcode ↗

Description

Given a string s and an integer k, reverse the first k characters for every 2k characters counting from the start of the string.

If there are fewer than k characters left, reverse all of them. If there are less than 2k but greater than or equal to k characters, then reverse the first k characters and leave the other as original.

Example 1:

Input: s = "abcdefg", k = 2
Output: "bacdfeg"

Example 2:

Input: s = "abcd", k = 2
Output: "bacd"

Solution