Add solution #729

Author: JoshCrozier

README.md

@@ -552,6 +552,7 @@
 725|[Split Linked List in Parts](./0725-split-linked-list-in-parts.js)|Medium|
 726|[Number of Atoms](./0726-number-of-atoms.js)|Hard|
 728|[Self Dividing Numbers](./0728-self-dividing-numbers.js)|Easy|
+729|[My Calendar I](./0729-my-calendar-i.js)|Medium|
 733|[Flood Fill](./0733-flood-fill.js)|Easy|
 735|[Asteroid Collision](./0735-asteroid-collision.js)|Medium|
 739|[Daily Temperatures](./0739-daily-temperatures.js)|Medium|

solutions/0729-my-calendar-i.js

@@ -0,0 +1,82 @@
+/**
+ * 729. My Calendar I
+ * https://leetcode.com/problems/my-calendar-i/
+ * Difficulty: Medium
+ *
+ * You are implementing a program to use as your calendar. We can add a new event if adding the
+ * event will not cause a double booking.
+ *
+ * A double booking happens when two events have some non-empty intersection (i.e., some moment
+ * is common to both events.).
+ *
+ * The event can be represented as a pair of integers startTime and endTime that represents a
+ * booking on the half-open interval [startTime, endTime), the range of real numbers x such
+ * that startTime <= x < endTime.
+ *
+ * Implement the MyCalendar class:
+ * - MyCalendar() Initializes the calendar object.
+ * - boolean book(int startTime, int endTime) Returns true if the event can be added to the
+ *   calendar successfully without causing a double booking. Otherwise, return false and do
+ *   not add the event to the calendar.
+ */
+
+class MyCalendar {
+  constructor() {
+    this.events = [];
+  }
+
+  /**
+   * @param {number} startTime
+   * @param {number} endTime
+   * @returns {boolean}
+   */
+  book(startTime, endTime) {
+    const event = [startTime, endTime];
+    const index = this.findInsertIndex(startTime);
+
+    if (this.overlapsPrevious(index - 1, startTime) || this.overlapsNext(index, endTime)) {
+      return false;
+    }
+
+    this.events.splice(index, 0, event);
+    return true;
+  }
+
+  /**
+   * @param {number} startTime
+   * @returns {number}
+   */
+  findInsertIndex(startTime) {
+    let left = 0;
+    let right = this.events.length;
+
+    while (left < right) {
+      const mid = Math.floor((left + right) / 2);
+      if (this.events[mid][0] > startTime) {
+        right = mid;
+      } else {
+        left = mid + 1;
+      }
+    }
+
+    return left;
+  }
+
+  /**
+   * @param {number} prevIndex
+   * @param {number} startTime
+   * @returns {boolean}
+   */
+  overlapsPrevious(prevIndex, startTime) {
+    return prevIndex >= 0 && this.events[prevIndex][1] > startTime;
+  }
+
+  /**
+   * @param {number} nextIndex
+   * @param {number} endTime
+   * @returns {boolean}
+   */
+  overlapsNext(nextIndex, endTime) {
+    return nextIndex < this.events.length && this.events[nextIndex][0] < endTime;
+  }
+}