Create 710-random-pick-with-blacklist.js

Author: everthis

710-random-pick-with-blacklist.js

@@ -0,0 +1,31 @@
+/**
+ * @param {number} N
+ * @param {number[]} blacklist
+ */
+const Solution = function (N, blacklist) {
+  this.map = new Map()
+  for (let b of blacklist) this.map.set(b, -1)
+  this.M = N - this.map.size
+  for (let b of blacklist) {
+    if (b < this.M) {
+      while (this.map.has(N - 1)) N--
+      this.map.set(b, N - 1)
+      N--
+    }
+  }
+}
+
+/**
+ * @return {number}
+ */
+Solution.prototype.pick = function () {
+  const p = Math.floor(Math.random() * this.M)
+  if (this.map.has(p)) return this.map.get(p)
+  return p
+}
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * var obj = new Solution(N, blacklist)
+ * var param_1 = obj.pick()
+ */