Create 376-wiggle-subsequence.js

Author: everthis

376-wiggle-subsequence.js

@@ -0,0 +1,17 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+const wiggleMaxLength = function(nums) {
+  if (nums.length < 2) return nums.length
+  let prevdiff = nums[1] - nums[0]
+  let count = prevdiff !== 0 ? 2 : 1
+  for (let i = 2; i < nums.length; i++) {
+    let diff = nums[i] - nums[i - 1]
+    if ((diff > 0 && prevdiff <= 0) || (diff < 0 && prevdiff >= 0)) {
+      count++
+      prevdiff = diff
+    }
+  }
+  return count
+}