From f2dcdbe94757d3ef88278e4f8c80281ce7baf5c9 Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Sat, 14 May 2022 16:32:23 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200541.=E5=8F=8D=E8=BD=AC?= =?UTF-8?q?=E5=AD=97=E7=AC=A6=E4=B8=B2II.md=20Scala=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0541.反转字符串II.md | 41 ++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/problems/0541.反转字符串II.md b/problems/0541.反转字符串II.md index 8c13a390..99d6ebe0 100644 --- a/problems/0541.反转字符串II.md +++ b/problems/0541.反转字符串II.md @@ -347,6 +347,47 @@ public class Solution } } ``` +Scala: +版本一: (正常解法) +```scala +object Solution { + def reverseStr(s: String, k: Int): String = { + val res = s.toCharArray // 转换为Array好处理 + for (i <- s.indices by 2 * k) { + // 如果i+k大于了res的长度，则需要全部翻转 + if (i + k > res.length) { + reverse(res, i, s.length - 1) + } else { + reverse(res, i, i + k - 1) + } + } + new String(res) + } + // 翻转字符串，从start到end + def reverse(s: Array[Char], start: Int, end: Int): Unit = { + var (left, right) = (start, end) + while (left < right) { + var tmp = s(left) + s(left) = s(right) + s(right) = tmp + left += 1 + right -= 1 + } + } +} +``` +版本二: 首先利用sliding每隔k个进行分割，随后转换为数组，再使用zipWithIndex添加每个数组的索引，紧接着利用map做变换，如果索引%2==0则说明需要翻转，否则原封不动，最后再转换为String +```scala +object Solution { + def reverseStr(s: String, k: Int): String = { + s.sliding(k, k) + .toArray + .zipWithIndex + .map(v => if (v._2 % 2 == 0) v._1.reverse else v._1) + .mkString + } +} +``` -----------------------