How often are these problems asked?
Frequency scores are based on crowdsourced interview reports. A higher score means the problem has been reported more often in recent SIG interviews.
Very Likely
75-100%
Likely
50-74%
Sometimes
25-49%
Rare
0-24%
Problem database last updated: June 20, 2025
S
SIG Coding Interview Questions
7 problems · 1 Easy, 4 Medium, 2 Hard · Ranked #179 of 458
Difficulty breakdown
1 Easy
14% · avg 23%
4 Medium
57% · avg 59%
2 Hard
29% · avg 18%
Top topics
array
71.4%
simulation
42.9%9.9x
string
28.6%
tree
14.3%2.6x
depth-first-search
14.3%1.6x
binary-search-tree
14.3%12.7x
Interview profile
Based on 7 reported problems, SIG interviews are significantly harder than average - 29% Hard vs 18% across all companies. The majority (57%) of questions are Medium difficulty, which is typical for companies that want to see solid fundamentals without excessive trick questions.
Compared to the industry average, SIG puts unusual emphasis on simulation (42.9% of problems, 9.9x the industry average). If you're short on time, these are the categories to double down on.
The most common topics are array (71.4%), simulation (42.9%), string (28.6%), tree (14.3%). Problems below are sorted by frequency, the ones at the top are asked most often.
All 7 problems
| Problem | Difficulty | Frequency | Topics | |
|---|---|---|---|---|
Validate Binary Search Tree Given the root of a binary tree, determine if it is a valid binary search tree (BST). | Medium | Very Likely | treedepth-first-searchbinary-search-tree | Solve |
Text Justification Given an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justifie... | Hard | Very Likely | arraystringsimulation | Solve |
Spiral Matrix Given an m x n matrix, return all elements of the matrix in spiral order. | Medium | Likely | arraymatrixsimulation | Solve |
Block Placement Queries There exists an infinite number line, with its origin at 0 and extending towards the positive x-axis. | Hard | Likely | arraybinary-searchbinary-indexed-tree | Solve |
Number of Black Blocks You are given two integers m and n representing the dimensions of a 0-indexed m x n grid. | Medium | Likely | arrayhash-tableenumeration | Solve |
Add Binary Given two binary strings a and b, return their sum as a binary string. | Easy | Likely | mathstringbit-manipulation | Solve |
Kth Largest Element in an Array Given an integer array nums and an integer k, return the kth largest element in the array. | Medium | Likely | arraydivide-and-conquersorting | Solve |
Validate Binary Search Tree
SolveGiven the root of a binary tree, determine if it is a valid binary search tree (BST).
MediumVery Likely
treedepth-first-searchbinary-search-tree
Text Justification
SolveGiven an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justifie...
HardVery Likely
arraystringsimulation
Spiral Matrix
SolveGiven an m x n matrix, return all elements of the matrix in spiral order.
MediumLikely
arraymatrixsimulation
Block Placement Queries
SolveThere exists an infinite number line, with its origin at 0 and extending towards the positive x-axis.
HardLikely
arraybinary-searchbinary-indexed-tree
Number of Black Blocks
SolveYou are given two integers m and n representing the dimensions of a 0-indexed m x n grid.
MediumLikely
arrayhash-tableenumeration
Add Binary
SolveGiven two binary strings a and b, return their sum as a binary string.
EasyLikely
mathstringbit-manipulation
Kth Largest Element in an Array
SolveGiven an integer array nums and an integer k, return the kth largest element in the array.
MediumLikely
arraydivide-and-conquersorting
Preparing for your SIG coding interview
SIG interviews focus heavily on array, simulation, string problems. If you're short on time, these are the categories to prioritize. The problems on this page are sorted by frequency, so start from the top and work your way down.
Beyond solving problems, practice explaining your approach. SIG interviewers care about your thought process - how you break down a problem, consider edge cases, and evaluate tradeoffs between solutions. A clean O(n) solution you can explain clearly beats an O(log n) solution you can't articulate.
Looking for more companies? Browse all 458 companies in our directory, or sharpen your fundamentals with our free data structure visualizers and AI-powered DSA tutor.
Frequently Asked Questions
What coding problems does SIG ask in interviews?add
SIG has been reported to ask 7 distinct coding problems. The most common topics are array, simulation, string. 1 are Easy difficulty, 4 are Medium, and 2 are Hard. Problems are sorted by frequency - the ones at the top are asked most often.
How hard are SIG coding interviews?add
Based on 7 reported problems, SIG interviews are significantly harder than average - 29% Hard vs 18% across all companies. 57% of questions are Medium difficulty. Focus on the high-frequency Medium problems first, then work through the Hard ones.
How should I prepare for a SIG coding interview?add
Start with the highest-frequency problems listed on this page. Focus on the core topics: array, simulation, string. Practice solving them under time pressure and explaining your approach out loud. Mock interviews with AI can simulate the real experience.
Other companies to explore
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