Google data scientist interviews test statistical reasoning, ML model design, SQL proficiency, A/B testing methodology, and Python-based algorithm implementation.
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coding
Medium
Verified Question
#1
1. Dictionary of Sorted Letters
Category: Array coding problem# Question Given a string where letters are sorted in alphabetical order, identify all letters that appear more than twice and record their first and...Input: Array
Output: Computed result
coding
Medium
Verified Question
#2
2. GPS Error Tracking
Category: Algorithm coding problem# Question You are tracking GPS location errors by comparing measured GPS locations against a set of "golden" (reference) locations. Each location...Input: List
Output: Computed result
coding
Hard
Verified Question
#3
3. Minimum Boxing Area
Category: Binary search coding problem# Question Design a data structure to maintain a dynamic set of points on a 2D coordinate plane. Support operations to insert points, remove points,...Input: List
Output: Integer
coding
Medium
Verified Question
#4
4. Reverse Segment of Linked List
Category: Linked list coding problem# Question Given a singly linked list, reverse the second half of the list and then interleave the nodes from the first half and the reversed second...Input: Linked list
Output: Computed result
coding
Medium
Verified Question
#5
5. Unpainted Segments
Category: Binary search coding problem# Question You are given a range [A, B] and a sequence of painting operations. For each operation [L, R], calculate the total length of unpainted...Input: Array of intervals
Output: Computed result
coding
Medium
Verified Question
#6
6. Running Tests With Failing Pairs
Category: Algorithm coding problem# Question You are given a set of test cases and a black-box function
runTests() that accepts a subset of these test cases and returns whether...Input: ListOutput: Integer
coding
Medium
Verified Question
#7
7. Connected Crop Allocation
Category: Grid/matrix coding problem# Question You are given an M x N garden grid and a list of crops, each requiring a specific number of plots. The total number of plots required by...Input: 2D grid
Output: Computed result
coding
Medium
Verified Question
#8
8. [CodeSignal] Maximum Zero-Sum Triplets
Category: Array coding problem# Question You are given an array
A of integers. A triplet is a sequence of three consecutive elements. A triplet is called zero-sum if the...Input: ArrayOutput: Computed result
coding
Easy
Verified Question
#9
9. [CodeSignal] Coin Table Game
Category: String coding problem# Question A player is playing a game in which coins are placed on and removed from a table. The game consists of multiple rounds. At the beginning...Input: String
Output: Computed result
coding
Medium
Verified Question
#10
10. Longest Match Tokenizer
Category: Array coding problemYou are given a text string
text and a dictionary array where each element is in the format "<key>:<id>". Here key is a token string and id...Input: ArrayOutput: Computed result
coding
Hard
Verified Question
#11
11. Dual Extremes Queue
Category: Queue-based coding problemDesign a
StreamBuffer class that buffers a stream of integer latency samples in FIFO order and supports O(1) access to both the minimum and maximum...Input: Integer(s)Output: Integer
coding
Medium
Verified Question
#12
12. Daily Branch Pruning
Category: Tree coding problemA file system manages a directory tree. Each day, all leaf directories (those with no child directories) are simultaneously removed. Directories that...Input: Array
Output: Array
coding
Medium
Verified Question
#13
13. Path Router
Category: Algorithm coding problem# Question Design a
PathRouter class that maps URL-like path patterns to handler names. Patterns may contain wildcard segments (*) that match any...Input: Number(s)Output: Computed result
coding
Medium
Verified Question
#14
14. Frequency Merge Tree
Category: Tree coding problem# Question Given a string, build a Frequency Merge Tree as follows: 1. Count the frequency of each character in the string. 2. Create a leaf node...Input: String
Output: Computed result
coding
Hard
Verified Question
#15
15. Expression Simplifier
Category: String coding problemGiven an algebraic expression string containing single lowercase-letter variables, the operators
+ and -, and parentheses ( and ), simplify...Input: StringOutput: Computed result
coding
Medium
Verified Question
#16
16. Largest Island Perimeter
Category: Grid/matrix coding problemYou are given an
m x n binary grid where each cell is either '1' (land) or '0' (water). A group of connected land cells (connected horizontally...Input: 2D gridOutput: Computed result
coding
Hard
Verified Question
#17
17. Interval Coverage Counter
Category: Interval-based coding problemGiven a list of closed intervals on the integer number line, build a data structure that efficiently answers point-coverage queries. A closed...Input: List
Output: Computed result
coding
Hard
dynamic programming
#1
1. [OA] Dynamic Programming — Build Efficient Advertisement Targeting for Google Ads
Google Ads needs a way to allocate budget efficiently to maximize conversions. Given a list of
- Output: An integer representing the maximum conversions.Example 1:
Input:
Output:
Explanation: We can spend on campaigns with conversions 200 and 300.Example 2:
Input:
Output:
Explanation: Spending on all campaigns gives maximum conversions.Constraints:
-
-
-
n campaigns with their individual expected conversions, calculate the maximum conversions achievable given a total budget of B.Problem statement: Implement a function maxConversions(campaigns: List[int], B: int) -> int to return the maximum conversions that can be achieved without exceeding the budget.- Input: A list of integers campaigns representing conversion estimates for each campaign and an integer B, the total budget available.- Output: An integer representing the maximum conversions.Example 1:
Input:
[200, 400, 300], B = 500Output:
3Explanation: We can spend on campaigns with conversions 200 and 300.Example 2:
Input:
[100, 150, 240, 300], B = 600Output:
4Explanation: Spending on all campaigns gives maximum conversions.Constraints:
-
1 <= n <= 100-
1 <= campaigns[i] <= 10^4-
1 <= B <= 10^6
coding
Hard
sliding window
#2
2. [OA] Sliding Window — Optimize YouTube View Analytics
Google Analytics for YouTube needs an efficient way to process and optimize view counts over varying time windows. Given a list of
- Output: An integer representing the maximum number of views within any time window of size
Input:
Output:
Explanation: The maximum views within any continuous window of size 3 are 3 views (from timestamps 3, 4, 5).Example 2:
Input:
Output:
Explanation: The timestamps 2, 2 and 3 yield the highest number of views in a window of size 2.Constraints:
-
-
-
n timestamps, determine the maximum number of views in any continuous time window of size k.Problem statement: Implement a function maxViewsInWindow(timestamps: List[int], k: int) -> int that returns the maximum views within any continuous time window of size k.- Input: A list timestamps of integers representing view timestamps and an integer k for the window size.- Output: An integer representing the maximum number of views within any time window of size
k.Example 1:Input:
[1, 2, 3, 4, 5], k = 3Output:
3Explanation: The maximum views within any continuous window of size 3 are 3 views (from timestamps 3, 4, 5).Example 2:
Input:
[1, 2, 2, 2, 3, 3, 4], k = 2Output:
4Explanation: The timestamps 2, 2 and 3 yield the highest number of views in a window of size 2.Constraints:
-
1 <= n <= 10^6-
0 <= timestamps[i] <= 10^9-
1 <= k <= nRelated Google Data Scientist interview prep
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