Advanced Interview Problems

Array Hash Table Breadth-First Search

Rank

#716HardFrequency: 100%High Priority

Max Stack

Linked List Stack Design Doubly-Linked List Ordered Set

Rank

#68HardFrequency: 100%High Priority

Text Justification

Array String Simulation

Rank

#750HardFrequency: 100%High Priority

Contain Virus

Array Depth-First Search Breadth-First Search Matrix Simulation

Rank

#269HardFrequency: 95.2%High Priority

Alien Dictionary

Array String Depth-First Search Breadth-First Search Graph Theory+2 more

Rank

#432HardFrequency: 93.8%High Priority

All O`one Data Structure

Rank

#1352HardFrequency: 93%High Priority

Maximum Profit in Job Scheduling

Array Binary Search Dynamic Programming Sorting

Rank

#329HardFrequency: 92.5%High Priority

Longest Increasing Path in a Matrix

Array Dynamic Programming Depth-First Search Breadth-First Search Graph Theory+4 more

Rank

#124HardFrequency: 90.2%High Priority

Binary Tree Maximum Path Sum

Dynamic Programming Tree Depth-First Search Binary Tree DP on Trees

Rank

#305HardFrequency: 89.9%High Priority

Number of Islands II

Array Hash Table Union-Find

#10

Rank

#42HardFrequency: 88%High Priority

Trapping Rain Water

Array Two Pointers Dynamic Programming Stack Monotonic Stack

#11

Rank

#1424HardFrequency: 82.4%High Priority

Maximum Candies You Can Get from Boxes

Array Breadth-First Search Graph Theory

#12

Rank

#564HardFrequency: 80.8%High Priority

Find the Closest Palindrome

Math String

#13

Rank

#2023HardFrequency: 79.4%High Priority

Design Movie Rental System

Array Hash Table Design Heap (Priority Queue)Ordered Set

#14

Rank

#127HardFrequency: 79%High Priority

Word Ladder

Hash Table String Breadth-First Search Bidirectional Search

#15

Rank

#460HardFrequency: 78.9%High Priority

LFU Cache

#16

Rank

#336HardFrequency: 78.6%High Priority

Palindrome Pairs

Array Hash Table String Trie Hash Function

#17

Rank

#631HardFrequency: 78.6%High Priority

Design Excel Sum Formula

Array Hash Table String Graph Theory Design+2 more

#18

Rank

#3608HardFrequency: 76.9%High Priority

Find the Number of Subsequences With Equal GCD

Array Math Dynamic Programming Number Theory Euclidean Algorithm+1 more

#19

Rank

#4HardFrequency: 76.8%High Priority

Median of Two Sorted Arrays

Array Binary Search Divide and Conquer

#20

Rank

#3105HardFrequency: 76.8%High Priority

Minimum Edge Reversals So Every Node Is Reachable

Dynamic Programming Depth-First Search Breadth-First Search Graph Theory

#21

Rank

#2147HardFrequency: 76.6%High Priority

The Score of Students Solving Math Expression

Array Hash Table Math String Dynamic Programming+2 more

#22

Rank

#1024HardFrequency: 76.6%High Priority

Triples with Bitwise AND Equal To Zero

Array Hash Table Bit Manipulation

#23

Rank

#2667HardFrequency: 76%High Priority

Maximum Frequency Score of a Subarray

Array Hash Table Math Stack Sliding Window

#24

Rank

#787HardFrequency: 75.6%High Priority

Sliding Puzzle

Array Dynamic Programming Backtracking Breadth-First Search Memoization+4 more

#25

Rank

#23HardFrequency: 75.1%High Priority

Merge k Sorted Lists

Linked List Divide and Conquer Heap (Priority Queue)Merge Sort Tournament Sort

#26

Rank

#76HardFrequency: 74.7%High Priority

Minimum Window Substring

Hash Table String Sliding Window

#27

Rank

#239HardFrequency: 74.4%High Priority

Sliding Window Maximum

Asked at Oracle

Array Queue Sliding Window Heap (Priority Queue)Monotonic Queue+1 more

#28

Rank

#51HardFrequency: 73.6%High Priority

N-Queens

Array Backtracking Algorithm X

#29

Rank

#212HardFrequency: 73.4%High Priority

Word Search II

Array String Backtracking Trie Matrix

#30

Rank

#2166HardFrequency: 73.2%High Priority

Number of Valid Move Combinations On Chessboard

Array String Backtracking Simulation

#31

Rank

#2301HardFrequency: 73.2%High Priority

Count Array Pairs Divisible by K

Array Hash Table Math Counting Number Theory+2 more

#32

Rank

#1583HardFrequency: 73.2%High Priority

Paint House III

Array Dynamic Programming

#33

Rank

#854HardFrequency: 72.8%High Priority

Making A Large Island

Array Depth-First Search Breadth-First Search Union-Find Matrix

#34

Rank

#2905HardFrequency: 71.9%High Priority

Count Paths That Can Form a Palindrome in a Tree

Hash Table Bit Manipulation Tree Depth-First Search

#35

Rank

#3690HardFrequency: 71.5%High Priority

Smallest Substring With Identical Characters I

Array Binary Search Enumeration

#36

Rank

#3706HardFrequency: 71.5%High Priority

Smallest Substring With Identical Characters II

String Binary Search

#37

Rank

#317HardFrequency: 71.4%High Priority

Shortest Distance from All Buildings

Array Breadth-First Search Matrix

#38

Rank

#2419HardFrequency: 69.8%High Priority

Subarray With Elements Greater Than Varying Threshold

Array Stack Union-Find Monotonic Stack

#39

Rank

#3181HardFrequency: 69.8%High Priority

Find Building Where Alice and Bob Can Meet

Array Binary Search Stack Binary Indexed Tree Segment Tree+2 more

#40

Rank

#3875HardFrequency: 69.8%High Priority

Maximum Good Subtree Score

Array Dynamic Programming Bit Manipulation Tree Depth-First Search+1 more

#41

Rank

#84HardFrequency: 69.6%High Priority

Largest Rectangle in Histogram

Array Stack Monotonic Stack Range Minimum/Maximum Query

#42

Rank

#1029HardFrequency: 69.1%High Priority

Vertical Order Traversal of a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Sorting+1 more

#43

Rank

#3435HardFrequency: 68.4%High Priority

Block Placement Queries

Array Binary Search Binary Indexed Tree Segment Tree Ordered Set

#44

Rank

#65HardFrequency: 68.2%High Priority

Valid Number

String

#45

Rank

#761HardFrequency: 67.9%High Priority

Employee Free Time

Array Sweep Line Sorting Heap (Priority Queue)

#46

Rank

#2415HardFrequency: 67.6%High Priority

Count the Number of Ideal Arrays

Math Dynamic Programming Combinatorics Number Theory Prime Factorization+1 more

#47

Rank

#3762HardFrequency: 67.6%High Priority

Maximize the Minimum Game Score

Array Binary Search Greedy

#48

Rank

#4215HardFrequency: 67.6%High Priority

Good Subsequence Queries

Array Math Segment Tree Number Theory

#49

Rank

#785HardFrequency: 66.8%High Priority

Basic Calculator III

Array (35)Hash Table (15)String (13)Breadth-First Search (11)Dynamic Programming (11)Depth-First Search (9)Stack (8)Math (8)

Math String Stack Recursion

#50

Rank

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Advanced Interview Problems

Challenging hard problems asked at top-tier tech companies for senior positions.

Total Problems

Easy

Medium

Hard

78%

Avg Frequency

Most Common Topics

Companies Asking These Questions

Uber (8)Airbnb (7)Infosys (6)Flipkart (5)PayPal (4)Meta (4)

Problems in This Collection

#833HardFrequency: 100%High Priority

Bus Routes

Array Hash Table Breadth-First Search

Rank

#716HardFrequency: 100%High Priority

Max Stack

Linked List Stack Design Doubly-Linked List Ordered Set

Rank

#68HardFrequency: 100%High Priority

Text Justification

Array String Simulation

Rank

#750HardFrequency: 100%High Priority

Contain Virus

Array Depth-First Search Breadth-First Search Matrix Simulation

Rank

#269HardFrequency: 95.2%High Priority

Alien Dictionary

Array String Depth-First Search Breadth-First Search Graph Theory+2 more

Rank

#432HardFrequency: 93.8%High Priority

All O`one Data Structure

Rank

#1352HardFrequency: 93%High Priority

Maximum Profit in Job Scheduling

Array Binary Search Dynamic Programming Sorting

Rank

#329HardFrequency: 92.5%High Priority

Longest Increasing Path in a Matrix

Array Dynamic Programming Depth-First Search Breadth-First Search Graph Theory+4 more

Rank

#124HardFrequency: 90.2%High Priority

Binary Tree Maximum Path Sum

Dynamic Programming Tree Depth-First Search Binary Tree DP on Trees

Rank

#305HardFrequency: 89.9%High Priority

Number of Islands II

Array Hash Table Union-Find

#10

Rank

#42HardFrequency: 88%High Priority

Trapping Rain Water

Array Two Pointers Dynamic Programming Stack Monotonic Stack

#11

Rank

#1424HardFrequency: 82.4%High Priority

Maximum Candies You Can Get from Boxes

Array Breadth-First Search Graph Theory

#12

Rank

#564HardFrequency: 80.8%High Priority

Find the Closest Palindrome

Math String

#13

Rank

#2023HardFrequency: 79.4%High Priority

Design Movie Rental System

Array Hash Table Design Heap (Priority Queue)Ordered Set

#14

Rank

#127HardFrequency: 79%High Priority

Word Ladder

Hash Table String Breadth-First Search Bidirectional Search

#15

Rank

#460HardFrequency: 78.9%High Priority

LFU Cache

#16

Rank

#336HardFrequency: 78.6%High Priority

Palindrome Pairs

Array Hash Table String Trie Hash Function

#17

Rank

#631HardFrequency: 78.6%High Priority

Design Excel Sum Formula

Array Hash Table String Graph Theory Design+2 more

#18

Rank

#3608HardFrequency: 76.9%High Priority

Find the Number of Subsequences With Equal GCD

Array Math Dynamic Programming Number Theory Euclidean Algorithm+1 more

#19

Rank

#4HardFrequency: 76.8%High Priority

Median of Two Sorted Arrays

Array Binary Search Divide and Conquer

#20

Rank

#3105HardFrequency: 76.8%High Priority

Minimum Edge Reversals So Every Node Is Reachable

Dynamic Programming Depth-First Search Breadth-First Search Graph Theory

#21

Rank

#2147HardFrequency: 76.6%High Priority

The Score of Students Solving Math Expression

Array Hash Table Math String Dynamic Programming+2 more

#22

Rank

#1024HardFrequency: 76.6%High Priority

Triples with Bitwise AND Equal To Zero

Array Hash Table Bit Manipulation

#23

Rank

#2667HardFrequency: 76%High Priority

Maximum Frequency Score of a Subarray

Array Hash Table Math Stack Sliding Window

#24

Rank

#787HardFrequency: 75.6%High Priority

Sliding Puzzle

Array Dynamic Programming Backtracking Breadth-First Search Memoization+4 more

#25

Rank

#23HardFrequency: 75.1%High Priority

Merge k Sorted Lists

Linked List Divide and Conquer Heap (Priority Queue)Merge Sort Tournament Sort

#26

Rank

#76HardFrequency: 74.7%High Priority

Minimum Window Substring

Hash Table String Sliding Window

#27

Rank

#239HardFrequency: 74.4%High Priority

Sliding Window Maximum

Asked at Oracle

Array Queue Sliding Window Heap (Priority Queue)Monotonic Queue+1 more

#28

Rank

#51HardFrequency: 73.6%High Priority

N-Queens

Array Backtracking Algorithm X

#29

Rank

#212HardFrequency: 73.4%High Priority

Word Search II

Array String Backtracking Trie Matrix

#30

Rank

#2166HardFrequency: 73.2%High Priority

Number of Valid Move Combinations On Chessboard

Array String Backtracking Simulation

#31

Rank

#2301HardFrequency: 73.2%High Priority

Count Array Pairs Divisible by K

Array Hash Table Math Counting Number Theory+2 more

#32

Rank

#1583HardFrequency: 73.2%High Priority

Paint House III

Array Dynamic Programming

#33

Rank

#854HardFrequency: 72.8%High Priority

Making A Large Island

Array Depth-First Search Breadth-First Search Union-Find Matrix

#34

Rank

#2905HardFrequency: 71.9%High Priority

Count Paths That Can Form a Palindrome in a Tree

Hash Table Bit Manipulation Tree Depth-First Search

#35

Rank

#3690HardFrequency: 71.5%High Priority

Smallest Substring With Identical Characters I

Array Binary Search Enumeration

#36

Rank

#3706HardFrequency: 71.5%High Priority

Smallest Substring With Identical Characters II

String Binary Search

#37

Rank

#317HardFrequency: 71.4%High Priority

Shortest Distance from All Buildings

Array Breadth-First Search Matrix

#38

Rank

#2419HardFrequency: 69.8%High Priority

Subarray With Elements Greater Than Varying Threshold

Array Stack Union-Find Monotonic Stack

#39

Rank

#3181HardFrequency: 69.8%High Priority

Find Building Where Alice and Bob Can Meet

Array Binary Search Stack Binary Indexed Tree Segment Tree+2 more

#40

Rank

#3875HardFrequency: 69.8%High Priority

Maximum Good Subtree Score

Array Dynamic Programming Bit Manipulation Tree Depth-First Search+1 more

#41

Rank

#84HardFrequency: 69.6%High Priority

Largest Rectangle in Histogram

Array Stack Monotonic Stack Range Minimum/Maximum Query

#42

Rank

#1029HardFrequency: 69.1%High Priority

Vertical Order Traversal of a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Sorting+1 more

#43

Rank

#3435HardFrequency: 68.4%High Priority

Block Placement Queries

Array Binary Search Binary Indexed Tree Segment Tree Ordered Set

#44

Rank

#65HardFrequency: 68.2%High Priority

Valid Number

String

#45

Rank

#761HardFrequency: 67.9%High Priority

Employee Free Time

Array Sweep Line Sorting Heap (Priority Queue)

#46

Rank

#2415HardFrequency: 67.6%High Priority

Count the Number of Ideal Arrays

Math Dynamic Programming Combinatorics Number Theory Prime Factorization+1 more

#47

Rank

#3762HardFrequency: 67.6%High Priority

Maximize the Minimum Game Score

Array Binary Search Greedy

#48

Rank

#4215HardFrequency: 67.6%High Priority

Good Subsequence Queries

Array Math Segment Tree Number Theory

#49

Rank

#785HardFrequency: 66.8%High Priority

Basic Calculator III