Breadth First Search Interview Questions

Rank

#286MediumFrequency: 100%

Walls and Gates

Rank

#750HardFrequency: 100%

Contain Virus

Array Depth-First Search Breadth-First Search Matrix Simulation

Rank

#200MediumFrequency: 97.3%

Number of Islands

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

Rank

#364MediumFrequency: 95.4%

Nested List Weight Sum II

Stack Depth-First Search Breadth-First Search

Rank

#269HardFrequency: 95.2%

Alien Dictionary

Array String Depth-First Search Breadth-First Search Graph Theory Topological Sort Directed Acyclic Graph

Rank

#314MediumFrequency: 93.4%

Binary Tree Vertical Order Traversal

Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree

Rank

#329HardFrequency: 92.5%

Longest Increasing Path in a Matrix

Array Dynamic Programming Depth-First Search Breadth-First Search Graph Theory Topological Sort Memoization Matrix Directed Acyclic Graph

Rank

#339MediumFrequency: 87.9%

Nested List Weight Sum

Depth-First Search Breadth-First Search

Rank

#694MediumFrequency: 86.6%

Number of Distinct Islands

Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function

#10

Rank

#210MediumFrequency: 85.9%

Course Schedule II

Depth-First Search Breadth-First Search Graph Theory Topological Sort

#11

Rank

#199MediumFrequency: 85.4%

Binary Tree Right Side View

Tree Depth-First Search Breadth-First Search Binary Tree

#12

Rank

#1190MediumFrequency: 82.4%

Smallest Common Region

Array Hash Table String Tree Depth-First Search Breadth-First Search Binary Lifting Lowest Common Ancestor

#13

Rank

#1424HardFrequency: 82.4%

Maximum Candies You Can Get from Boxes

Array Breadth-First Search Graph Theory

#14

Rank

#207MediumFrequency: 82.3%

Course Schedule

Depth-First Search Breadth-First Search Graph Theory Topological Sort Directed Acyclic Graph

#15

Rank

#1036MediumFrequency: 82%

Rotting Oranges

#16

Rank

#1171MediumFrequency: 80.9%

Shortest Path in Binary Matrix

#17

Rank

#127HardFrequency: 79%

Word Ladder

Hash Table String Breadth-First Search Bidirectional Search

#18

Rank

#4180MediumFrequency: 78.4%

Pythagorean Distance Nodes in a Tree

Tree Breadth-First Search

#19

Rank

#3105HardFrequency: 76.8%

Minimum Edge Reversals So Every Node Is Reachable

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

#20

Rank

#1007MediumFrequency: 76.6%

Numbers With Same Consecutive Differences

Backtracking Breadth-First Search

#21

Rank

#787HardFrequency: 75.6%

Sliding Puzzle

Array Dynamic Programming Backtracking Breadth-First Search Memoization Matrix Heuristic Search Bidirectional Search A* Search

#22

Rank

#322MediumFrequency: 73.2%

Coin Change

Array Dynamic Programming Breadth-First Search Knapsack Problem Complete Knapsack

#23

Rank

#854HardFrequency: 72.8%

Making A Large Island

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

#24

Rank

#317HardFrequency: 71.4%

Shortest Distance from All Buildings

#25

Rank

#133MediumFrequency: 70.5%

Clone Graph

Hash Table Depth-First Search Breadth-First Search Graph Theory

#26

Rank

#399MediumFrequency: 70.2%

Evaluate Division

Array String Depth-First Search Breadth-First Search Union-Find Graph Theory Shortest Path Bellman–Ford Algorithm Floyd–Warshall Algorithm

#27

Rank

#1029HardFrequency: 69.1%

Vertical Order Traversal of a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Sorting Binary Tree

#28

Rank

#960HardFrequency: 66.4%

Minimize Malware Spread

Asked at Salesforce

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#29

Rank

#893MediumFrequency: 65.7%

All Nodes Distance K in Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#30

Rank

#1409HardFrequency: 65.5%

Minimum Number of Flips to Convert Binary Matrix to Zero Matrix

Array Hash Table Bit Manipulation Breadth-First Search Matrix

#31

Rank

#803MediumFrequency: 65.5%

Cheapest Flights Within K Stops

Dynamic Programming Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Shortest Path

#32

Rank

#2726HardFrequency: 65.2%

Minimum Reverse Operations

Array Hash Table Breadth-First Search Union-Find Ordered Set

#33

Rank

#104EasyFrequency: 65%

Maximum Depth of Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#34

Rank

#3863MediumFrequency: 64.9%

Power Grid Maintenance

Asked at Salesforce

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory Heap (Priority Queue)Ordered Set

#35

Rank

#101EasyFrequency: 63.4%

Symmetric Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#36

Rank

#297HardFrequency: 63.4%

Serialize and Deserialize Binary Tree

String Tree Depth-First Search Breadth-First Search Design Binary Tree

#37

Rank

#1414HardFrequency: 63.3%

Shortest Path in a Grid with Obstacles Elimination

Asked at Databricks

#38

Rank

#2584MediumFrequency: 62.5%

Number of Nodes With Value One

Array Tree Depth-First Search Breadth-First Search Binary Tree

#39

Rank

#971MediumFrequency: 61.8%

Shortest Bridge

Array Depth-First Search Breadth-First Search Matrix

#40

Rank

#721MediumFrequency: 61.4%

Accounts Merge

Array Hash Table String Depth-First Search Breadth-First Search Union-Find Sorting

#41

Rank

#743MediumFrequency: 61.1%

Closest Leaf in a Binary Tree

Asked at Databricks

Tree Depth-First Search Breadth-First Search Binary Tree

#42

Rank

#675HardFrequency: 59.8%

Cut Off Trees for Golf Event

Array Breadth-First Search Heap (Priority Queue)Matrix

#43

Rank

#417MediumFrequency: 59.8%

Pacific Atlantic Water Flow

Array Depth-First Search Breadth-First Search Matrix

#44

Rank

#695MediumFrequency: 59.3%

Max Area of Island

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

#45

Rank

#490MediumFrequency: 57.5%

The Maze

Array Depth-First Search Breadth-First Search Matrix

#46

Rank

#2344HardFrequency: 57.5%

Escape the Spreading Fire

Array Binary Search Breadth-First Search Matrix

#47

Rank

#2583HardFrequency: 57.5%

Divide Nodes Into the Maximum Number of Groups

Depth-First Search Breadth-First Search Union-Find Graph Theory

#48

Rank

#1308MediumFrequency: 57%

Smallest String With Swaps

Array Hash Table String Depth-First Search Breadth-First Search Union-Find Sorting

#49

Rank

#103MediumFrequency: 55.5%

Binary Tree Zigzag Level Order Traversal

#50

Rank

#102MediumFrequency: 54.4%

Binary Tree Level Order Traversal

#51

Rank

#998MediumFrequency: 54.4%

Check Completeness of a Binary Tree

#52

Rank

#922MediumFrequency: 54.4%

Possible Bipartition

Depth-First Search Breadth-First Search Union-Find Graph Theory Graph Coloring Bipartite Graph

#53

Rank

#3613MediumFrequency: 54.1%

Maximize Amount After Two Days of Conversions

Array String Depth-First Search Breadth-First Search Graph Theory

#54

Rank

#505MediumFrequency: 54.1%

The Maze II

Array Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path Dijkstra's Algorithm Heuristic Search A* Search

#55

Rank

#3271MediumFrequency: 53.4%

Count the Number of Houses at a Certain Distance I

Breadth-First Search Graph Theory Prefix Sum

#56

Rank

#1431MediumFrequency: 53.4%

All Ancestors of a Node in a Directed Acyclic Graph

Depth-First Search Breadth-First Search Graph Theory Topological Sort Directed Acyclic Graph

#57

Rank

#733EasyFrequency: 53%

Flood Fill

Array Depth-First Search Breadth-First Search Matrix

#58

Rank

#2461MediumFrequency: 52.9%

Amount of Time for Binary Tree to Be Infected

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#59

Rank

#662MediumFrequency: 52.9%

Maximum Width of Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#60

Rank

#407HardFrequency: 52.9%

Trapping Rain Water II

Array Breadth-First Search Heap (Priority Queue)Matrix

#61

Rank

#542MediumFrequency: 51.3%

01 Matrix

Array Dynamic Programming Breadth-First Search Matrix

#62

Rank

#547MediumFrequency: 50.7%

Number of Provinces

Depth-First Search Breadth-First Search Union-Find Graph Theory

#63

Rank

#301HardFrequency: 50.1%

Remove Invalid Parentheses

String Backtracking Breadth-First Search

#64

Rank

#753MediumFrequency: 49.9%

Open the Lock

Array Hash Table String Breadth-First Search Bidirectional Search

#65

Rank

#999MediumFrequency: 49.9%

Regions Cut By Slashes

Array Hash Table Depth-First Search Breadth-First Search Union-Find Matrix Planar Graph

#66

Rank

#116MediumFrequency: 48.8%

Populating Next Right Pointers in Each Node

Linked List Tree Depth-First Search Breadth-First Search Binary Tree

#67

Rank

#617EasyFrequency: 48.8%

Merge Two Binary Trees

Tree Depth-First Search Breadth-First Search Binary Tree

#68

Rank

#100EasyFrequency: 48.1%

Same Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#69

Rank

#365MediumFrequency: 48%

Water and Jug Problem

Math Depth-First Search Breadth-First Search Bézout's Lemma Euclidean Algorithm Greatest Common Divisor Extended Euclidean Algorithm

#70

Rank

#690MediumFrequency: 47.5%

Employee Importance

Array Hash Table Tree Depth-First Search Breadth-First Search

#71

Rank

#1558MediumFrequency: 47.5%

Course Schedule IV

Depth-First Search Breadth-First Search Graph Theory Topological Sort

#72

Rank

#1643MediumFrequency: 47.5%

Number of Nodes in the Sub-Tree With the Same Label

Hash Table Tree Depth-First Search Breadth-First Search Counting DP on Trees

#73

Rank

#2038MediumFrequency: 47.5%

Nearest Exit from Entrance in Maze

#74

Rank

#130MediumFrequency: 46.9%

Surrounded Regions

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

#75

Rank

#895HardFrequency: 45.2%

Shortest Path to Get All Keys

Array Bit Manipulation Breadth-First Search Matrix

#76

Rank

#1485HardFrequency: 44.8%

Minimum Cost to Make at Least One Valid Path in a Grid

Array Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path 0-1 BFS Dijkstra's Algorithm

#77

Rank

#261MediumFrequency: 44.7%

Graph Valid Tree

Depth-First Search Breadth-First Search Union-Find Graph Theory

#78

Rank

#515MediumFrequency: 44.7%

Find Largest Value in Each Tree Row

Tree Depth-First Search Breadth-First Search Binary Tree

#79

Rank

#529MediumFrequency: 44.4%

Minesweeper

Array Depth-First Search Breadth-First Search Matrix

#80

Rank

#126HardFrequency: 44.1%

Word Ladder II

Hash Table String Backtracking Breadth-First Search Bidirectional Search

#81

Rank

#1576MediumFrequency: 44%

Reorder Routes to Make All Paths Lead to the City Zero

Depth-First Search Breadth-First Search Graph Theory

#82

Rank

#226EasyFrequency: 43%

Invert Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#83

Rank

#1142MediumFrequency: 43%

Minimum Knight Moves

Asked at Databricks

Breadth-First Search Heuristic Search Bidirectional Search A* Search

#84

Rank

#3825MediumFrequency: 42.7%

Apply Substitutions

Array Hash Table String Depth-First Search Breadth-First Search Graph Theory Topological Sort

#85

Rank

#323MediumFrequency: 42.2%

Number of Connected Components in an Undirected Graph

Depth-First Search Breadth-First Search Union-Find Graph Theory

#86

Rank

#2914MediumFrequency: 41.6%

Find the Safest Path in a Grid

Array Binary Search Breadth-First Search Union-Find Heap (Priority Queue)Matrix

#87

Rank

#945MediumFrequency: 41.4%

Snakes and Ladders

Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Shortest Path Dijkstra's Algorithm

#88

Rank

#744MediumFrequency: 41.2%

Network Delay Time

Asked at Salesforce

#89

Rank

#1442MediumFrequency: 40.9%

Number of Operations to Make Network Connected

Depth-First Search Breadth-First Search Union-Find Graph Theory

#90

Rank

#1554MediumFrequency: 40.7%

Minimum Time to Collect All Apples in a Tree

Hash Table Tree Depth-First Search Breadth-First Search DP on Trees

#91

Rank

#112EasyFrequency: 40.5%

Path Sum

Tree Depth-First Search Breadth-First Search Binary Tree

#92

Rank

#117MediumFrequency: 40%

Populating Next Right Pointers in Each Node II

Linked List Tree Depth-First Search Breadth-First Search Binary Tree

#93

Rank

#794HardFrequency: 40%

Swim in Rising Water

Array Binary Search Depth-First Search Breadth-First Search Union-Find Minimax Heap (Priority Queue)Matrix Dijkstra's Algorithm

#94

Rank

#1931MediumFrequency: 40%

Shortest Path in a Hidden Grid

Array Depth-First Search Breadth-First Search Matrix Interactive

#95

Rank

#871MediumFrequency: 39.4%

Keys and Rooms

Depth-First Search Breadth-First Search Graph Theory

#96

Rank

#765HardFrequency: 39.4%

Serialize and Deserialize N-ary Tree

String Tree Depth-First Search Breadth-First Search

#97

Rank

#1177MediumFrequency: 39.1%

Tree Diameter

Tree Depth-First Search Breadth-First Search Graph Theory Topological Sort DP on Trees

#98

Rank

#582MediumFrequency: 39.1%

Kill Process

Array Hash Table Tree Depth-First Search Breadth-First Search

#99

Rank

#896MediumFrequency: 38.5%

Smallest Subtree with all the Deepest Nodes

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor DP on Trees

#100

Rank

#279MediumFrequency: 38.2%

Perfect Squares

Math Dynamic Programming Breadth-First Search Knapsack Problem Complete Knapsack

#101

Rank

#2564MediumFrequency: 37.9%

Most Profitable Path in a Tree

Array Tree Depth-First Search Breadth-First Search Graph Theory

#102

Rank

#2588HardFrequency: 37.9%

Maximum Number of Points From Grid Queries

Array Two Pointers Breadth-First Search Union-Find Sorting Heap (Priority Queue)Matrix

#103

Rank

#1753MediumFrequency: 37.3%

Path With Minimum Effort

Array Binary Search Depth-First Search Breadth-First Search Union-Find Heap (Priority Queue)Matrix Dijkstra's Algorithm

#104

Rank

#2206MediumFrequency: 36.9%

Detonate the Maximum Bombs

Array Math Depth-First Search Breadth-First Search Graph Theory Geometry

#105

Rank

#653EasyFrequency: 35.7%

Two Sum IV - Input is a BST

Hash Table Two Pointers Tree Depth-First Search Breadth-First Search Binary Search Tree Binary Tree

#106

Rank

#1544MediumFrequency: 35.7%

Count Good Nodes in Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#107

Rank

#820MediumFrequency: 35.1%

Find Eventual Safe States

Depth-First Search Breadth-First Search Graph Theory Topological Sort Kosaraju's Algorithm Tarjan's SCC Algorithm

#108

Rank

#1076MediumFrequency: 35%

Brace Expansion

String Backtracking Stack Breadth-First Search Sorting

#109

Rank

#1428MediumFrequency: 34.3%

Jump Game III

Array Depth-First Search Breadth-First Search

#110

Rank

#801MediumFrequency: 34.2%

Is Graph Bipartite?

Depth-First Search Breadth-First Search Union-Find Graph Theory Graph Coloring Bipartite Graph

#111

Rank

#2035MediumFrequency: 34.2%

Count Sub Islands

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

#112

Rank

#869HardFrequency: 34.2%

Similar String Groups

Array Hash Table String Depth-First Search Breadth-First Search Union-Find

#113

Rank

#1218MediumFrequency: 34%

Lowest Common Ancestor of Deepest Leaves

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor DP on Trees

#114

Rank

#684MediumFrequency: 33.7%

Redundant Connection

Depth-First Search Breadth-First Search Union-Find Graph Theory

#115

Rank

#463EasyFrequency: 33.3%

Island Perimeter

Array Depth-First Search Breadth-First Search Matrix

#116

Rank

#1380MediumFrequency: 33.3%

Number of Closed Islands

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

#117

Rank

#1347HardFrequency: 33.3%

Distance to a Cycle in Undirected Graph

Depth-First Search Breadth-First Search Graph Theory Topological Sort

#118

Rank

#1254MediumFrequency: 33%

Deepest Leaves Sum

Tree Depth-First Search Breadth-First Search Binary Tree

#119

Rank

#2121EasyFrequency: 32.8%

Find if Path Exists in Graph

Depth-First Search Breadth-First Search Union-Find Graph Theory

#120

Rank

#3983HardFrequency: 31.3%

Minimum Operations to Equalize Binary String

Math String Breadth-First Search Union-Find Ordered Set

#121

Rank

#1492MediumFrequency: 31.3%

Time Needed to Inform All Employees

#122

Rank

#2545HardFrequency: 31.1%

Height of Binary Tree After Subtree Removal Queries

Array Tree Depth-First Search Breadth-First Search Binary Tree

#123

Rank

#310MediumFrequency: 30.4%

Minimum Height Trees

Depth-First Search Breadth-First Search Graph Theory Topological Sort

#124

Rank

#877HardFrequency: 29.7%

Shortest Path Visiting All Nodes

Dynamic Programming Bit Manipulation Breadth-First Search Graph Theory Bitmask

#125

Rank

#513MediumFrequency: 29.3%

Find Bottom Left Tree Value

Tree Depth-First Search Breadth-First Search Binary Tree

#126

Rank

#672MediumFrequency: 29.3%

Bulb Switcher II

Math Bit Manipulation Depth-First Search Breadth-First Search

#127

Rank

#2568MediumFrequency: 29.3%

Minimum Fuel Cost to Report to the Capital

Tree Depth-First Search Breadth-First Search Graph Theory

#128

Rank

#2646MediumFrequency: 29.1%

Kth Largest Sum in a Binary Tree

Tree Breadth-First Search Sorting Binary Tree

#129

Rank

#530EasyFrequency: 28.9%

Minimum Absolute Difference in BST

Tree Depth-First Search Breadth-First Search Binary Search Tree Binary Tree

#130

Rank

#1116MediumFrequency: 28.1%

Maximum Level Sum of a Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#131

Rank

#404EasyFrequency: 28.1%

Sum of Left Leaves

Tree Depth-First Search Breadth-First Search Binary Tree

#132

Rank

#2403MediumFrequency: 27.8%

Count Unreachable Pairs of Nodes in an Undirected Graph

Depth-First Search Breadth-First Search Union-Find Graph Theory

#133

Rank

#3933MediumFrequency: 27.8%

Minimum Jumps to Reach End via Prime Teleportation

Array Hash Table Math Breadth-First Search Number Theory

#134

Rank

#1201MediumFrequency: 27.3%

Delete Tree Nodes

Array Tree Depth-First Search Breadth-First Search DP on Trees

#135

Rank

#1609EasyFrequency: 27.3%

Find All The Lonely Nodes

Tree Depth-First Search Breadth-First Search Binary Tree

#136

Rank

#3467MediumFrequency: 27.3%

Find the Level of Tree with Minimum Sum

Tree Depth-First Search Breadth-First Search Binary Tree

#137

Rank

#550MediumFrequency: 27.3%

Shortest Path to Get Food

#138

Rank

#3386HardFrequency: 27.3%

Find Edges in Shortest Paths

Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Shortest Path

#139

Rank

#1296HardFrequency: 27.2%

Kth Ancestor of a Tree Node

Binary Search Dynamic Programming Bit Manipulation Tree Depth-First Search Breadth-First Search Design Binary Lifting

#140

Rank

#1073MediumFrequency: 27.2%

Number of Enclaves

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

#141

Rank

#1498EasyFrequency: 26.7%

Find a Corresponding Node of a Binary Tree in a Clone of That Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#142

Rank

#1959MediumFrequency: 26.7%

Minimum Path Cost in a Hidden Grid

Array Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Interactive Shortest Path

#143

Rank

#1229MediumFrequency: 26.5%

Shortest Path with Alternating Colors

Breadth-First Search Graph Theory

#144

Rank

#1624MediumFrequency: 26.5%

Clone Binary Tree With Random Pointer

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#145

Rank

#2677MediumFrequency: 26.5%

Cousins in Binary Tree II

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#146

Rank

#1099MediumFrequency: 25.4%

Path With Maximum Minimum Value

Array Binary Search Depth-First Search Breadth-First Search Union-Find Heap (Priority Queue)Matrix Dijkstra's Algorithm

#147

Rank

#107MediumFrequency: 25.3%

Binary Tree Level Order Traversal II

#148

Rank

#3439HardFrequency: 25.3%

Find Minimum Diameter After Merging Two Trees

Tree Depth-First Search Breadth-First Search Graph Theory

#149

Rank

#433MediumFrequency: 25.1%

Minimum Genetic Mutation

Hash Table String Breadth-First Search Bidirectional Search

#150

Rank

#449MediumFrequency: 25.1%

Serialize and Deserialize BST

String Tree Depth-First Search Breadth-First Search Design Binary Search Tree Binary Tree

#151

Rank

#711HardFrequency: 25.1%

Number of Distinct Islands II

Array Hash Table Depth-First Search Breadth-First Search Union-Find Sorting Matrix Hash Function

#152

Rank

#813MediumFrequency: 25.1%

All Paths From Source to Target

Backtracking Depth-First Search Breadth-First Search Graph Theory Directed Acyclic Graph

#153

Rank

#1243MediumFrequency: 25.1%

Sum of Nodes with Even-Valued Grandparent

Tree Depth-First Search Breadth-First Search Binary Tree

#154

Rank

#1436MediumFrequency: 25.1%

Get Watched Videos by Your Friends

Array Hash Table Breadth-First Search Graph Theory Sorting

#155

Rank

#2558MediumFrequency: 25.1%

Minimum Number of Operations to Sort a Binary Tree by Level

#156

Rank

#637EasyFrequency: 25.1%

Average of Levels in Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#157

Rank

#1275MediumFrequency: 25.1%

Validate Binary Tree Nodes

Tree Depth-First Search Breadth-First Search Union-Find Graph Theory Binary Tree

#158

Rank

#1368MediumFrequency: 25.1%

Web Crawler Multithreaded

Depth-First Search Breadth-First Search Concurrency

#159

Rank

#111EasyFrequency: 25%

Minimum Depth of Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#160

Rank

#3752MediumFrequency: 24.6%

Unit Conversion II

Array Math Depth-First Search Breadth-First Search Graph Theory

#161

Rank

#1117MediumFrequency: 24.6%

As Far from Land as Possible

Array Dynamic Programming Breadth-First Search Matrix

#162

Rank

#1396MediumFrequency: 24.4%

Count Servers that Communicate

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

#163

Rank

#2213HardFrequency: 24.4%

Find All People With Secret

Depth-First Search Breadth-First Search Union-Find Graph Theory Sorting

#164

Rank

#1883MediumFrequency: 23.6%

Find Distance in a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree Binary Lifting Lowest Common Ancestor

#165

Rank

#2101HardFrequency: 23.3%

Last Day Where You Can Still Cross

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

#166

Rank

#2375HardFrequency: 23.3%

Minimum Obstacle Removal to Reach Corner

Array Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path 0-1 BFS Dijkstra's Algorithm

#167

Rank

#1447HardFrequency: 22.1%

Jump Game IV

#168

Rank

#737MediumFrequency: 22%

Sentence Similarity II

Array Hash Table String Depth-First Search Breadth-First Search Union-Find

#169

Rank

#1271MediumFrequency: 21.5%

Web Crawler

String Depth-First Search Breadth-First Search Interactive

#170

Rank

#2662MediumFrequency: 21.5%

Check Knight Tour Configuration

Array Depth-First Search Breadth-First Search Matrix Simulation

#171

Rank

#1731MediumFrequency: 21.5%

Even Odd Tree

#172

Rank

#514HardFrequency: 20.9%

Freedom Trail

String Dynamic Programming Depth-First Search Breadth-First Search

#173

Rank

#2641MediumFrequency: 20.9%

Disconnect Path in a Binary Matrix by at Most One Flip

Array Dynamic Programming Depth-First Search Breadth-First Search Matrix

#174

Rank

#302HardFrequency: 20.9%

Smallest Rectangle Enclosing Black Pixels

Array Binary Search Depth-First Search Breadth-First Search Matrix

#175

Rank

#685HardFrequency: 20.9%

Redundant Connection II

Depth-First Search Breadth-First Search Union-Find Graph Theory

#176

Rank

#964HardFrequency: 20.3%

Minimize Malware Spread II

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#177

Rank

#3720MediumFrequency: 20.3%

Minimize the Maximum Edge Weight of Graph

Binary Search Depth-First Search Breadth-First Search Graph Theory Shortest Path

#178

Rank

#1568MediumFrequency: 20%

Pseudo-Palindromic Paths in a Binary Tree

Bit Manipulation Tree Depth-First Search Breadth-First Search Binary Tree

#179

Rank

#1634MediumFrequency: 20%

Clone N-ary Tree

Hash Table Tree Depth-First Search Breadth-First Search

#180

Rank

#799EasyFrequency: 19.5%

Minimum Distance Between BST Nodes

Tree Depth-First Search Breadth-First Search Binary Search Tree Binary Tree

#181

Rank

#884HardFrequency: 19.5%

K-Similar Strings

Hash Table String Breadth-First Search

#182

Rank

#770HardFrequency: 19.5%

Couples Holding Hands

Greedy Depth-First Search Breadth-First Search Union-Find Graph Theory

#183

Rank

#1188HardFrequency: 18%

Brace Expansion II

Hash Table String Backtracking Stack Breadth-First Search Sorting

#184

Rank

#1876MediumFrequency: 18%

Map of Highest Peak

#185

Rank

#2104MediumFrequency: 18%

Operations on Tree

Array Hash Table Tree Depth-First Search Breadth-First Search Design

#186

Rank

#2183MediumFrequency: 18%

Minimum Operations to Convert Number

Array Breadth-First Search

#187

Rank

#1747MediumFrequency: 18%

Lexicographically Smallest String After Applying Operations

String Depth-First Search Breadth-First Search Enumeration

#188

Rank

#1663MediumFrequency: 18%

Detect Cycles in 2D Grid

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

#189

Rank

#955MediumFrequency: 16.4%

Complete Binary Tree Inserter

Tree Breadth-First Search Design Binary Tree

#190

Rank

#1387MediumFrequency: 16.4%

Find Elements in a Contaminated Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Design Binary Tree

#191

Rank

#1745MediumFrequency: 16.4%

Find Nearest Right Node in Binary Tree

#192

Rank

#1796MediumFrequency: 16.4%

Correct a Binary Tree

Hash Table Tree Depth-First Search Breadth-First Search Binary Tree

#193

Rank

#2314MediumFrequency: 16.4%

Remove All Ones With Row and Column Flips II

Array Bit Manipulation Breadth-First Search Matrix

#194

Rank

#1493HardFrequency: 16.4%

Frog Position After T Seconds

Tree Depth-First Search Breadth-First Search Graph Theory

#195

Rank

#3517MediumFrequency: 16.1%

Shortest Distance After Road Addition Queries I

Array Breadth-First Search Graph Theory

#196

Rank

#2711HardFrequency: 16.1%

Minimum Time to Visit a Cell In a Grid

Array Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path

#197

Rank

#2793MediumFrequency: 16.1%

Count the Number of Complete Components

Depth-First Search Breadth-First Search Union-Find Graph Theory

#198

Rank

#1035EasyFrequency: 15.7%

Cousins in Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#199

Rank

#3558MediumFrequency: 14.6%

Find a Safe Walk Through a Grid

Array Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path

#200

Rank

#2582MediumFrequency: 14.6%

Minimum Score of a Path Between Two Cities

Depth-First Search Breadth-First Search Union-Find Graph Theory

#201

Rank

#655MediumFrequency: 12.6%

Print Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#202

Rank

#2171HardFrequency: 12.6%

Second Minimum Time to Reach Destination

Breadth-First Search Graph Theory Shortest Path Dijkstra's Algorithm K Shortest Path

#203

Rank

#2493MediumFrequency: 12.6%

Reverse Odd Levels of Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#204

Rank

#764MediumFrequency: 12%

N-ary Tree Level Order Traversal

Tree Breadth-First Search

#205

Rank

#2764MediumFrequency: 12%

Maximum Number of Fish in a Grid

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

#206

Rank

#2409HardFrequency: 12%

Number of Increasing Paths in a Grid

Array Dynamic Programming Depth-First Search Breadth-First Search Graph Theory Topological Sort Memoization Matrix

#207

Rank

#1005EasyFrequency: 10.5%

Univalued Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#208

Rank

#3633MediumFrequency: 10.5%

Maximize the Number of Target Nodes After Connecting Trees I

#209

Rank

#1389HardFrequency: 10.5%

Minimum Moves to Move a Box to Their Target Location

Array Breadth-First Search Heap (Priority Queue)Matrix

#210

Rank

#1309HardFrequency: 8.1%

Sort Items by Groups Respecting Dependencies

Depth-First Search Breadth-First Search Graph Theory Topological Sort Directed Acyclic Graph

#211

Rank

#3645HardFrequency: 8.1%

Maximize the Number of Target Nodes After Connecting Trees II

#212

Rank

#2671HardFrequency: 8%

Shortest Cycle in a Graph

Breadth-First Search Graph Theory

#213

Rank

#1757MediumFrequency: 7.3%

Minimum Jumps to Reach Home

#214

Rank

#1104MediumFrequency: 7.3%

Coloring A Border

Array Depth-First Search Breadth-First Search Matrix

#215

Rank

#2439HardFrequency: 7.3%

Longest Cycle in a Graph

Depth-First Search Breadth-First Search Graph Theory Topological Sort Kosaraju's Algorithm Tarjan's SCC Algorithm

#216

Rank

#1106HardFrequency: 7.3%

Escape a Large Maze

Array Hash Table Depth-First Search Breadth-First Search Bidirectional Search

#217

Rank

#774EasyFrequency: 7.2%

Maximum Depth of N-ary Tree

#218

Rank

#3837MediumFrequency: 7.2%

Grid Teleportation Traversal

Array Hash Table Breadth-First Search Matrix

#219

Rank

#3561MediumFrequency: 7.2%

Remove Methods From Project

Depth-First Search Breadth-First Search Graph Theory

#220

Rank

#1691HardFrequency: 5.5%

Minimum Number of Days to Disconnect Island

Array Depth-First Search Breadth-First Search Matrix Strongly Connected Component Articulation Point

#221

Rank

#488HardFrequency: 5.5%

Zuma Game

String Dynamic Programming Stack Breadth-First Search Memoization

#222

Rank

#623MediumFrequency: 5%

Add One Row to Tree

Tree Depth-First Search Breadth-First Search Binary Tree

#223

Rank

#3560HardFrequency: 5%

Maximum Number of Moves to Kill All Pawns

Array Math Bit Manipulation Breadth-First Search Game Theory Bitmask

#224

Rank

#2420HardFrequency: 5%

Closest Node to Path in Tree

Array Tree Depth-First Search Breadth-First Search

#225

Rank

#2103MediumFrequency: 5%

Find All Groups of Farmland

Array Depth-First Search Breadth-First Search Matrix

#226

Rank

#499HardFrequency: 5%

The Maze III

Array String Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue)Matrix Shortest Path Dijkstra's Algorithm Heuristic Search A* Search

#227

Rank

#3823MediumFrequency: 5%

Count Islands With Total Value Divisible by K

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

#228

Rank

#2445MediumFrequency: 5%

Reachable Nodes With Restrictions

Array Hash Table Tree Depth-First Search Breadth-First Search Union-Find Graph Theory

#229

Rank

#4035HardFrequency: 5%

Maximum Partition Factor

Array Binary Search Depth-First Search Breadth-First Search Union-Find Graph Theory

#230

Rank

#1507MediumFrequency: 5%

Check if There is a Valid Path in a Grid

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

#231

Rank

#3478HardFrequency: 5%

Check if the Rectangle Corner Is Reachable

Array Math Depth-First Search Breadth-First Search Union-Find Geometry

#232

Rank

#2151MediumFrequency: 5%

The Time When the Network Becomes Idle

Array Breadth-First Search Graph Theory

#233

Rank

#3809MediumFrequency: 5%

Properties Graph

Array Hash Table Depth-First Search Breadth-First Search Union-Find Graph Theory

#234

Rank

#3928MediumFrequency: 5%

Split and Merge Array Transformation