From abe00238f44718c49b9442c26e7f7b01f84be3e4 Mon Sep 17 00:00:00 2001
From: ZongqinWang <1722249371@qq.com>
Date: Fri, 13 May 2022 16:37:39 +0800
Subject: [PATCH 1/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200001.=E4=B8=A4?=
=?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/0001.两数之和.md | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/problems/0001.两数之和.md b/problems/0001.两数之和.md
index 9571a773..141e66f3 100644
--- a/problems/0001.两数之和.md
+++ b/problems/0001.两数之和.md
@@ -274,6 +274,27 @@ class Solution {
}
}
```
-
+Scala:
+```scala
+object Solution {
+ // 导入包
+ import scala.collection.mutable
+ def twoSum(nums: Array[Int], target: Int): Array[Int] = {
+ // key存储值，value存储下标
+ val map = new mutable.HashMap[Int, Int]()
+ for (i <- nums.indices) {
+ val tmp = target - nums(i) // 计算差值
+ // 如果这个差值存在于map，则说明找到了结果
+ if (map.contains(tmp)) {
+ return Array(map.get(tmp).get, i)
+ }
+ // 如果不包含把当前值与其下标放到map
+ map.put(nums(i), i)
+ }
+ // 如果没有找到直接返回一个空的数组，return关键字可以省略
+ new Array[Int](2)
+ }
+}
+```
-----------------------
From 53379c023fe935398801f41aad3dd0399b2d7d73 Mon Sep 17 00:00:00 2001
From: ZongqinWang <1722249371@qq.com>
Date: Fri, 13 May 2022 17:28:14 +0800
Subject: [PATCH 2/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200454.=E5=9B=9B?=
=?UTF-8?q?=E6=95=B0=E7=9B=B8=E5=8A=A0II.md=20Scala=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
problems/0454.四数相加II.md | 36 +++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/problems/0454.四数相加II.md b/problems/0454.四数相加II.md
index a6cd413b..d4aba8fa 100644
--- a/problems/0454.四数相加II.md
+++ b/problems/0454.四数相加II.md
@@ -318,5 +318,41 @@ impl Solution {
}
```
+Scala:
+```scala
+object Solution {
+ // 导包
+ import scala.collection.mutable
+ def fourSumCount(nums1: Array[Int], nums2: Array[Int], nums3: Array[Int], nums4: Array[Int]): Int = {
+ // 定义一个HashMap，key存储值，value存储该值出现的次数
+ val map = new mutable.HashMap[Int, Int]()
+ // 遍历前两个数组，把他们所有可能的情况都记录到map
+ for (i <- nums1.indices) {
+ for (j <- nums2.indices) {
+ val tmp = nums1(i) + nums2(j)
+ // 如果包含该值，则对他的key加1，不包含则添加进去
+ if (map.contains(tmp)) {
+ map.put(tmp, map.get(tmp).get + 1)
+ } else {
+ map.put(tmp, 1)
+ }
+ }
+ }
+ var res = 0 // 结果变量
+ // 遍历后两个数组
+ for (i <- nums3.indices) {
+ for (j <- nums4.indices) {
+ val tmp = -(nums3(i) + nums4(j))
+ // 如果map中存在该值，结果就+=value
+ if (map.contains(tmp)) {
+ res += map.get(tmp).get
+ }
+ }
+ }
+ // 返回最终结果，可以省略关键字return
+ res
+ }
+}
+```
-----------------------
From 16c6abff54ec4b85d0891ed12914f538da7b8332 Mon Sep 17 00:00:00 2001
From: ZongqinWang <1722249371@qq.com>
Date: Fri, 13 May 2022 21:02:07 +0800
Subject: [PATCH 3/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200383.=E8=B5=8E?=
=?UTF-8?q?=E9=87=91=E4=BF=A1.md=20Scala=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
problems/0383.赎金信.md | 62 ++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md
index 5d9e8295..8e4cbbf8 100644
--- a/problems/0383.赎金信.md
+++ b/problems/0383.赎金信.md
@@ -360,6 +360,68 @@ impl Solution {
}
}
```
+Scala:
+版本一: 使用数组作为哈希表
+```scala
+object Solution {
+ def canConstruct(ransomNote: String, magazine: String): Boolean = {
+ // 如果magazine的长度小于ransomNote的长度，必然是false
+ if (magazine.length < ransomNote.length) {
+ return false
+ }
+ // 定义一个数组，存储magazine字符出现的次数
+ val map: Array[Int] = new Array[Int](26)
+ // 遍历magazine字符串，对应的字符+=1
+ for (i <- magazine.indices) {
+ map(magazine(i) - 'a') += 1
+ }
+ // 遍历ransomNote
+ for (i <- ransomNote.indices) {
+ if (map(ransomNote(i) - 'a') > 0)
+ map(ransomNote(i) - 'a') -= 1
+ else return false
+ }
+ // 如果上面没有返回false，直接返回true，关键字return可以省略
+ true
+ }
+}
+```
+版本二: 使用HashMap
+```scala
+object Solution {
+ import scala.collection.mutable
+ def canConstruct(ransomNote: String, magazine: String): Boolean = {
+ // 如果magazine的长度小于ransomNote的长度，必然是false
+ if (magazine.length < ransomNote.length) {
+ return false
+ }
+ // 定义map，key是字符，value是字符出现的次数
+ val map = new mutable.HashMap[Char, Int]()
+ // 遍历magazine，把所有的字符都记录到map里面
+ for (i <- magazine.indices) {
+ val tmpChar = magazine(i)
+ // 如果map包含该字符，那么对应的value++，否则添加该字符
+ if (map.contains(tmpChar)) {
+ map.put(tmpChar, map.get(tmpChar).get + 1)
+ } else {
+ map.put(tmpChar, 1)
+ }
+ }
+ // 遍历ransomNote
+ for (i <- ransomNote.indices) {
+ val tmpChar = ransomNote(i)
+ // 如果map包含并且该字符的value大于0，则匹配成功，map对应的--，否则直接返回false
+ if (map.contains(tmpChar) && map.get(tmpChar).get > 0) {
+ map.put(tmpChar, map.get(tmpChar).get - 1)
+ } else {
+ return false
+ }
+ }
+ // 如果上面没有返回false，直接返回true，关键字return可以省略
+ true
+ }
+}
+```
-----------------------
