feat: Find Median From Data Stream

Author: gwbaik9717

find-median-from-data-stream/gwbaik9717.js

@@ -0,0 +1,55 @@
+// Time complexity: O(n)
+// Space complexity: O(n)
+
+var MedianFinder = function () {
+  this.arr = [];
+};
+
+/**
+ * @param {number} num
+ * @return {void}
+ */
+MedianFinder.prototype.addNum = function (num) {
+  if (this.arr.length === 0) {
+    this.arr.push(num);
+    return;
+  }
+
+  let left = 0;
+  let right = this.arr.length - 1;
+
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+
+    if (this.arr[mid] > num) {
+      right = mid - 1;
+      continue;
+    }
+
+    left = mid + 1;
+  }
+
+  // insert in left
+  const sliced = this.arr.slice(left);
+  this.arr = [...this.arr.slice(0, left), num, ...sliced];
+};
+
+/**
+ * @return {number}
+ */
+MedianFinder.prototype.findMedian = function () {
+  if (this.arr.length % 2 === 0) {
+    return (
+      (this.arr[this.arr.length / 2] + this.arr[this.arr.length / 2 - 1]) / 2
+    );
+  }
+
+  return this.arr[(this.arr.length - 1) / 2];
+};
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * var obj = new MedianFinder()
+ * obj.addNum(num)
+ * var param_2 = obj.findMedian()
+ */