Create 481-magical-string.js

Author: everthis

481-magical-string.js

@@ -0,0 +1,21 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+const magicalString = function(n) {
+  const queue = []
+  let one = true
+  let count1 = 0
+  while (n-- > 0) {
+    queue.shift()
+    let c = one ? 1 : 2
+    one = !one
+    queue.push(c)
+    count1 += 2 - c
+    if (queue[0] === 2 && n-- > 0) {
+      queue.push(c)
+      count1 += 2 - c
+    }
+  }
+  return count1
+}