From a53da7b4e205468bb7f870b5b46093c42923d429 Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Sat, 14 May 2022 14:41:14 +0800 Subject: [PATCH 1/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200015.=E4=B8=89?= =?UTF-8?q?=E6=95=B0=E4=B9=8B=E5=92=8C.md=20Scala=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0015.三数之和.md | 43 +++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md index cc184c87..1764d244 100644 --- a/problems/0015.三数之和.md +++ b/problems/0015.三数之和.md @@ -616,6 +616,49 @@ public class Solution } } ``` +Scala: +```scala +object Solution { + // 导包 + import scala.collection.mutable.ListBuffer + import scala.util.control.Breaks.{break, breakable} + def threeSum(nums: Array[Int]): List[List[Int]] = { + // 定义结果集,最后需要转换为List + val res = ListBuffer[List[Int]]() + val nums_tmp = nums.sorted // 对nums进行排序 + for (i <- nums_tmp.indices) { + // 如果要排的第一个数字大于0,直接返回结果 + if (nums_tmp(i) > 0) { + return res.toList + } + // 如果i大于0并且和前一个数字重复,则跳过本次循环,相当于continue + breakable { + if (i > 0 && nums_tmp(i) == nums_tmp(i - 1)) { + break + } else { + var left = i + 1 + var right = nums_tmp.length - 1 + while (left < right) { + var sum = nums_tmp(i) + nums_tmp(left) + nums_tmp(right) // 求三数之和 + if (sum < 0) left += 1 + else if (sum > 0) right -= 1 + else { + res += List(nums_tmp(i), nums_tmp(left), nums_tmp(right)) // 如果等于0 添加进结果集 + // 为了避免重复,对left和right进行移动 + while (left < right && nums_tmp(left) == nums_tmp(left + 1)) left += 1 + while (left < right && nums_tmp(right) == nums_tmp(right - 1)) right -= 1 + left += 1 + right -= 1 + } + } + } + } + } + // 最终返回需要转换为List,return关键字可以省略 + res.toList + } +} +``` -----------------------
From 68eed4af5b1f43e7ac65093dd00c7497f88885cc Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Sat, 14 May 2022 15:26:29 +0800 Subject: [PATCH 2/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200018.=E5=9B=9B?= =?UTF-8?q?=E6=95=B0=E4=B9=8B=E5=92=8C.md=20Scala=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0018.四数之和.md | 45 ++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) diff --git a/problems/0018.四数之和.md b/problems/0018.四数之和.md index ee70cb69..6cbd40c2 100644 --- a/problems/0018.四数之和.md +++ b/problems/0018.四数之和.md @@ -522,6 +522,49 @@ public class Solution } } ``` - +Scala: +```scala +object Solution { + // 导包 + import scala.collection.mutable.ListBuffer + import scala.util.control.Breaks.{break, breakable} + def fourSum(nums: Array[Int], target: Int): List[List[Int]] = { + val res = ListBuffer[List[Int]]() + val nums_tmp = nums.sorted // 先排序 + for (i <- nums_tmp.indices) { + breakable { + if (i > 0 && nums_tmp(i) == nums_tmp(i - 1)) { + break // 如果该值和上次的值相同,跳过本次循环,相当于continue + } else { + for (j <- i + 1 until nums_tmp.length) { + breakable { + if (j > i + 1 && nums_tmp(j) == nums_tmp(j - 1)) { + break // 同上 + } else { + // 双指针 + var (left, right) = (j + 1, nums_tmp.length - 1) + while (left < right) { + var sum = nums_tmp(i) + nums_tmp(j) + nums_tmp(left) + nums_tmp(right) + if (sum == target) { + // 满足要求,直接加入到集合里面去 + res += List(nums_tmp(i), nums_tmp(j), nums_tmp(left), nums_tmp(right)) + while (left < right && nums_tmp(left) == nums_tmp(left + 1)) left += 1 + while (left < right && nums_tmp(right) == nums_tmp(right - 1)) right -= 1 + left += 1 + right -= 1 + } else if (sum < target) left += 1 + else right -= 1 + } + } + } + } + } + } + } + // 最终返回的res要转换为List,return关键字可以省略 + res.toList + } +} +``` -----------------------