Google Software Engineer Interview Experience — Four Onsite Rounds: Roster Merge, AdService, Magical String Pairs

Onsite Round 1 (Technical)

Given a list of people and their shift schedules, return a final merged schedule that shows each time segment (start time, end time) and the list of everyone on shift during that segment.

Example input:

roster = [
["Mary", 10, 40],
["John", 30, 50],
["Peter", 50, 80],
["Crystal", 100, 150],
["Jane", 120, 180]
]

Example output:

res = [
[10, 30, ["Mary"]],
[30, 40, ["Mary", "John"]],
[40, 50, ["John"]],
[50, 80, ["Peter"]],
[80, 100, []],
[100, 120, ["Crystal"]],
[120, 150, ["Crystal", "Jane"]],
[150, 180, ["Jane"]]
]

Onsite Round 2 (Googlyness & Leadership)

Questions and follow-ups based on my resume and personal experience:

1. Deep dives into the project details on my resume, to understand what my specific responsibilities and contributions were.
2. The classic Googlyness behavioral questions on teamwork, communication, and handling challenges.

Onsite Round 3 (Technical)

Implement an ad service class AdService with two APIs:

1. InsertAd: takes a content (str) and a score (int).
2. GetAd: returns an ad.

GetAd has to satisfy three conditions:

1. Each call must return the ad with the highest current score.
2. No ad can be returned twice in a row.
3. After an ad is returned, its score is decreased by 1.

Onsite Round 4 (Technical)

Given a string s made up entirely of lowercase letters. Two non-empty strings s1 and s2 are called a magical string pair if the sets of distinct characters they contain are exactly the same.

Find the total number of triples (i, j, k) that satisfy:

1. The index constraint i <= j < k.
2. The substring s1 (s[i: j+1]) and the substring s2 (s[j+1: k+1]) form a magical string pair.