添加 0376.摆动序列.md Scala版本

Author: wzqwtt

problems/0376.摆动序列.md

@@ -375,7 +375,31 @@ function wiggleMaxLength(nums: number[]): number {
 };
 ```
 
+### Scala
+
+```scala
+object Solution {
+  def wiggleMaxLength(nums: Array[Int]): Int = {
+    if (nums.length <= 1) return nums.length
+    var result = 1
+    var curDiff = 0 // 当前一对的差值
+    var preDiff = 0 // 前一对的差值
+
+    for (i <- 1 until nums.length) {
+      curDiff = nums(i) - nums(i - 1) // 计算当前这一对的差值
+      // 当 curDiff > 0 的情况，preDiff <= 0
+      // 当 curDiff < 0 的情况，preDiff >= 0
+      // 这两种情况算是两个峰值
+      if ((curDiff > 0 && preDiff <= 0) || (curDiff < 0 && preDiff >= 0)) {
+        result += 1 // 结果集加 1
+        preDiff = curDiff // 当前差值赋值给上一轮
+      }
+    }
 
+    result
+  }
+}
+```
 
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