add: 数据流中第一个唯一的数字

src/array/first-unique-number-in-data-stream.js

@@ -0,0 +1,23 @@
+/**
+ * @param nums: a continuous stream of numbers
+ * @param number: a number
+ * @return: returns the first unique number
+ */
+export const firstUniqueNumber = function (nums, number) {
+  const due = new Set()
+  const queue = new Set()
+  for (const n of nums) {
+    if (queue.has(n)) {
+      queue.delete(n)
+      due.add(n)
+    } else if (!due.has(n)) {
+      queue.add(n)
+    }
+
+    if (n === number) break
+  }
+
+  if (!due.has(number) && !queue.has(number)) return -1
+
+  return Array.from(queue)[0] || -1
+}