I was referred by a friend. After 1-2 weeks, I was contacted by a recruiter.

The first stage was composed of two phone interviews. These interviews involved algorithm questions. The first was about grouping anagrams, and the second was about range intersections.

After I passed these interviews, I was invited for a day of onsite interviews. There were three onsite interviews: one was non-technical (about my background), and the other two were technical (mostly algorithms and coding). Between the two technical interviews, I went for a coffee break with an employee and had the chance to ask him more questions about his work and about Facebook in general.

How to get out from a maze.

You have a vector with the heights of an island (at point 1, point 2, etc.) and you want to know how much water would remain on this island (without flowing away).

Write a function that takes a list of words as input and returns a list of those words bucketized by anagrams with duplicates removed.

Example: Input: ["star", "rats", "car", "arc", "arts", "rats", "bar"] Output: [["star", "rats", "arts"], ["car", "arc"], ["bar"]]

Given two interval ranges, create a function to tell me if these ranges intersect. Both start and end are inclusive: [start, end].

Given two interval ranges that intersect, create a function to merge the two ranges into a single continuous range.

Create a function that takes a group of unsorted, unorganized intervals, merges any intervals that intersect, and sorts them. The result should be a group of sorted, non-intersecting intervals.

Create a function to merge a new interval into a group of sorted, non-intersecting intervals. After the merge, all intervals should remain non-intersecting. You are given the function definition below.