Solutions & Explanations

Browse 4,030+ detailed solutions with multiple approaches, code in Python, Java, C++ and more.

4,030 Solutions961 Easy2102 Medium967 Hard

Title	Difficulty	Acceptance	Topics	Solution
1601. Maximum Number of Achievable Transfer Requests	Hard	64.5%	Array Backtracking+2	Read
1602. Find Nearest Right Node in Binary Tree	Medium	75.2%	Binary Tree Breadth-First Search+1	Read
1603. Design Parking System	Easy	87.2%	Counting Design+1	Read
1604. Alert Using Same Key-Card Three or More Times in a One Hour Period	Medium	46.0%	Array Hash Table+2	Read
1605. Find Valid Matrix Given Row and Column Sums	Medium	83.0%	Array Greedy+1	Read
1606. Find Servers That Handled Most Number of Requests	Hard	45.3%	Array Greedy+2	Read
1607. Sellers With No Sales	Easy	54.4%	Database	Read
1608. Special Array With X Elements Greater Than or Equal X	Easy	66.8%	Array Binary Search+1	Read
1609. Even Odd Tree	Medium	67.1%	Binary Tree Breadth-First Search+1	Read
1610. Maximum Number of Visible Points	Hard	38.1%	Array Geometry+3	Read
1611. Minimum One Bit Operations to Make Integers Zero	Hard	78.5%	Bit Manipulation Dynamic Programming+1	Read
1612. Check If Two Expression Trees are Equivalent	Medium	71.8%	Binary Tree Counting+3	Read
1613. Find the Missing IDs	Medium	73.0%	Database	Read
1614. Maximum Nesting Depth of the Parentheses	Easy	84.8%	Stack String	Read
1615. Maximal Network Rank	Medium	65.9%	Graph	Read
1616. Split Two Strings to Make Palindrome	Medium	32.8%	String Two Pointers	Read
1617. Count Subtrees With Max Distance Between Cities	Hard	67.4%	Bit Manipulation Bitmask+3	Read
1618. Maximum Font to Fit a Sentence in a Screen	Medium	62.0%	Array Binary Search+2	Read
1619. Mean of Array After Removing Some Elements	Easy	72.2%	Array Sorting	Read
1620. Coordinate With Maximum Network Quality	Medium	40.0%	Array Enumeration	Read
1621. Number of Sets of K Non-Overlapping Line Segments	Medium	69.3%	Combinatorics Dynamic Programming+1	Read
1622. Fancy Sequence	Hard	41.3%	Design Math+1	Read
1623. All Valid Triplets That Can Represent a Country	Easy	81.8%	Database	Read
1624. Largest Substring Between Two Equal Characters	Easy	68.5%	Hash Table String	Read
1625. Lexicographically Smallest String After Applying Operations	Medium	79.4%	Breadth-First Search Depth-First Search+2	Read
1626. Best Team With No Conflicts	Medium	50.9%	Array Dynamic Programming+1	Read
1627. Graph Connectivity With Threshold	Hard	49.9%	Array Math+2	Read
1628. Design an Expression Tree With Evaluate Function	Medium	82.4%	Array Binary Tree+4	Read
1629. Slowest Key	Easy	59.7%	Array String	Read
1630. Arithmetic Subarrays	Medium	83.7%	Array Hash Table+1	Read
1631. Path With Minimum Effort	Medium	64.1%	Array Binary Search+5	Read
1632. Rank Transform of a Matrix	Hard	42.1%	Array Graph+4	Read
1633. Percentage of Users Attended a Contest	Easy	58.6%	Database	Read
1634. Add Two Polynomials Represented as Linked Lists	Medium	61.1%	Linked List Math+1	Read
1635. Hopper Company Queries I	Hard	47.7%	Database	Read
1636. Sort Array by Increasing Frequency	Easy	80.8%	Array Hash Table+1	Read
1637. Widest Vertical Area Between Two Points Containing No Points	Easy	87.3%	Array Sorting	Read
1638. Count Substrings That Differ by One Character	Medium	72.4%	Dynamic Programming Enumeration+2	Read
1639. Number of Ways to Form a Target String Given a Dictionary	Hard	56.6%	Array Dynamic Programming+1	Read
1640. Check Array Formation Through Concatenation	Easy	57.3%	Array Hash Table	Read
1641. Count Sorted Vowel Strings	Medium	79.2%	Combinatorics Dynamic Programming+1	Read
1642. Furthest Building You Can Reach	Medium	50.8%	Array Greedy+1	Read
1643. Kth Smallest Instructions	Hard	44.7%	Array Combinatorics+2	Read
1644. Lowest Common Ancestor of a Binary Tree II	Medium	69.6%	Binary Tree Depth-First Search+1	Read
1645. Hopper Company Queries II	Hard	39.1%	Database	Read
1646. Get Maximum in Generated Array	Easy	51.4%	Array Simulation	Read
1647. Minimum Deletions to Make Character Frequencies Unique	Medium	61.3%	Greedy Hash Table+2	Read
1648. Sell Diminishing-Valued Colored Balls	Medium	29.9%	Array Binary Search+4	Read
1649. Create Sorted Array through Instructions	Hard	42.1%	Array Binary Indexed Tree+5	Read
1650. Lowest Common Ancestor of a Binary Tree III	Medium	83.0%	Binary Tree Hash Table+2	Read

#1601Hard

Maximum Number of Achievable Transfer Requests

ArrayBacktrackingBit Manipulation+1

Acceptance: 64.5%

#1602Medium

Find Nearest Right Node in Binary Tree

Binary TreeBreadth-First SearchTree

Acceptance: 75.2%

#1603Easy

Design Parking System

CountingDesignSimulation

Acceptance: 87.2%

#1604Medium

Alert Using Same Key-Card Three or More Times in a One Hour Period

ArrayHash TableSorting+1

Acceptance: 46.0%

#1605Medium

Find Valid Matrix Given Row and Column Sums

ArrayGreedyMatrix

Acceptance: 83.0%

#1606Hard

Find Servers That Handled Most Number of Requests

ArrayGreedyHeap (Priority Queue)+1

Acceptance: 45.3%

#1607Easy

Sellers With No Sales

Database

Acceptance: 54.4%

#1608Easy

Special Array With X Elements Greater Than or Equal X

ArrayBinary SearchSorting

Acceptance: 66.8%

#1609Medium

Even Odd Tree

Binary TreeBreadth-First SearchTree

Acceptance: 67.1%

#1610Hard

Maximum Number of Visible Points

ArrayGeometryMath+2

Acceptance: 38.1%

#1611Hard

Minimum One Bit Operations to Make Integers Zero

Bit ManipulationDynamic ProgrammingMemoization

Acceptance: 78.5%

#1612Medium

Check If Two Expression Trees are Equivalent

Binary TreeCountingDepth-First Search+2

Acceptance: 71.8%

#1613Medium

Find the Missing IDs

Database

Acceptance: 73.0%

#1614Easy

Maximum Nesting Depth of the Parentheses

StackString

Acceptance: 84.8%

#1615Medium

Maximal Network Rank

Graph

Acceptance: 65.9%

#1616Medium

Split Two Strings to Make Palindrome

StringTwo Pointers

Acceptance: 32.8%

#1617Hard

Count Subtrees With Max Distance Between Cities

Bit ManipulationBitmaskDynamic Programming+2

Acceptance: 67.4%

#1618Medium

Maximum Font to Fit a Sentence in a Screen

ArrayBinary SearchInteractive+1

Acceptance: 62.0%

#1619Easy

Mean of Array After Removing Some Elements

ArraySorting

Acceptance: 72.2%

#1620Medium

Coordinate With Maximum Network Quality

ArrayEnumeration

Acceptance: 40.0%

#1621Medium

Number of Sets of K Non-Overlapping Line Segments

CombinatoricsDynamic ProgrammingMath

Acceptance: 69.3%

#1622Hard

Fancy Sequence

DesignMathSegment Tree

Acceptance: 41.3%

#1623Easy

All Valid Triplets That Can Represent a Country

Database

Acceptance: 81.8%

#1624Easy

Largest Substring Between Two Equal Characters

Hash TableString

Acceptance: 68.5%

#1625Medium

Lexicographically Smallest String After Applying Operations

Breadth-First SearchDepth-First SearchEnumeration+1

Acceptance: 79.4%

#1626Medium

Best Team With No Conflicts

ArrayDynamic ProgrammingSorting

Acceptance: 50.9%

#1627Hard

Graph Connectivity With Threshold

ArrayMathNumber Theory+1

Acceptance: 49.9%

#1628Medium

Design an Expression Tree With Evaluate Function

ArrayBinary TreeDesign+3

Acceptance: 82.4%

#1629Easy

Slowest Key

ArrayString

Acceptance: 59.7%

#1630Medium

Arithmetic Subarrays

ArrayHash TableSorting

Acceptance: 83.7%

#1631Medium

Path With Minimum Effort

ArrayBinary SearchBreadth-First Search+4

Acceptance: 64.1%

#1632Hard

Rank Transform of a Matrix

ArrayGraphMatrix+3

Acceptance: 42.1%

#1633Easy

Percentage of Users Attended a Contest

Database

Acceptance: 58.6%

#1634Medium

Add Two Polynomials Represented as Linked Lists

Linked ListMathTwo Pointers

Acceptance: 61.1%

#1635Hard

Hopper Company Queries I

Database

Acceptance: 47.7%

#1636Easy

Sort Array by Increasing Frequency

ArrayHash TableSorting

Acceptance: 80.8%

#1637Easy

Widest Vertical Area Between Two Points Containing No Points

ArraySorting

Acceptance: 87.3%

#1638Medium

Count Substrings That Differ by One Character

Dynamic ProgrammingEnumerationHash Table+1

Acceptance: 72.4%

#1639Hard

Number of Ways to Form a Target String Given a Dictionary

ArrayDynamic ProgrammingString

Acceptance: 56.6%

#1640Easy

Check Array Formation Through Concatenation

ArrayHash Table

Acceptance: 57.3%

#1641Medium

Count Sorted Vowel Strings

CombinatoricsDynamic ProgrammingMath

Acceptance: 79.2%

#1642Medium

Furthest Building You Can Reach

ArrayGreedyHeap (Priority Queue)

Acceptance: 50.8%

#1643Hard

Kth Smallest Instructions

ArrayCombinatoricsDynamic Programming+1

Acceptance: 44.7%

#1644Medium

Lowest Common Ancestor of a Binary Tree II

Binary TreeDepth-First SearchTree

Acceptance: 69.6%

#1645Hard

Hopper Company Queries II

Database

Acceptance: 39.1%

#1646Easy

Get Maximum in Generated Array

ArraySimulation

Acceptance: 51.4%

#1647Medium

Minimum Deletions to Make Character Frequencies Unique

GreedyHash TableSorting+1

Acceptance: 61.3%

#1648Medium

Sell Diminishing-Valued Colored Balls

ArrayBinary SearchGreedy+3

Acceptance: 29.9%

#1649Hard

Create Sorted Array through Instructions

ArrayBinary Indexed TreeBinary Search+4

Acceptance: 42.1%

#1650Medium

Lowest Common Ancestor of a Binary Tree III

Binary TreeHash TableTree+1

Acceptance: 83.0%

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