[LeetCode] 541. Reverse String II

轉自LeetCode

Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less 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 left the other as original.

Example:

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

Restrictions:

1. The string consists of lower English letters only.
2. Length of the given string and k will in the range [1, 10000]

<Solution>

思考方式

• 把字串用 2k 個分成一組，前面 k 個反轉，後面不動

code 如下(參考資料)

Java