Solutions & Explanations

Browse 4,029+ detailed solutions with multiple approaches, code in Python, Java, C++ and more.

4,029 Solutions961 Easy2102 Medium966 Hard

Title	Difficulty	Acceptance	Topics	Solution
951. Flip Equivalent Binary Trees	Medium	69.8%	Binary Tree Depth-First Search+1	Read
952. Largest Component Size by Common Factor	Hard	43.8%	Array Hash Table+3	Read
953. Verifying an Alien Dictionary	Easy	55.9%	Array Hash Table+1	Read
954. Array of Doubled Pairs	Medium	39.7%	Array Greedy+2	Read
955. Delete Columns to Make Sorted II	Medium	49.7%	Array Greedy+1	Read
956. Tallest Billboard	Hard	52.0%	Array Dynamic Programming	Read
957. Prison Cells After N Days	Medium	39.0%	Array Bit Manipulation+2	Read
958. Check Completeness of a Binary Tree	Medium	59.0%	Binary Tree Breadth-First Search+1	Read
959. Regions Cut By Slashes	Medium	77.8%	Array Breadth-First Search+4	Read
960. Delete Columns to Make Sorted III	Hard	72.7%	Array Dynamic Programming+1	Read
961. N-Repeated Element in Size 2N Array	Easy	79.9%	Array Hash Table	Read
962. Maximum Width Ramp	Medium	55.5%	Array Monotonic Stack+1	Read
963. Minimum Area Rectangle II	Medium	55.9%	Array Geometry+1	Read
964. Least Operators to Express Number	Hard	48.3%	Dynamic Programming Math+1	Read
965. Univalued Binary Tree	Easy	72.9%	Binary Tree Breadth-First Search+2	Read
966. Vowel Spellchecker	Medium	61.4%	Array Hash Table+1	Read
967. Numbers With Same Consecutive Differences	Medium	59.1%	Backtracking Breadth-First Search	Read
968. Binary Tree Cameras	Hard	47.7%	Binary Tree Depth-First Search+2	Read
969. Pancake Sorting	Medium	71.7%	Array Greedy+2	Read
970. Powerful Integers	Medium	44.5%	Enumeration Hash Table+1	Read
971. Flip Binary Tree To Match Preorder Traversal	Medium	51.9%	Binary Tree Depth-First Search+1	Read
972. Equal Rational Numbers	Hard	46.7%	Math String	Read
973. K Closest Points to Origin	Medium	69.4%	Array Divide and Conquer+5	Read
974. Subarray Sums Divisible by K	Medium	56.7%	Array Hash Table+1	Read
975. Odd Even Jump	Hard	41.1%	Array Dynamic Programming+3	Read
976. Largest Perimeter Triangle	Easy	62.1%	Array Greedy+2	Read
977. Squares of a Sorted Array	Easy	73.7%	Array Sorting+1	Read
978. Longest Turbulent Subarray	Medium	49.0%	Array Dynamic Programming+1	Read
979. Distribute Coins in Binary Tree	Medium	77.2%	Binary Tree Depth-First Search+1	Read
980. Unique Paths III	Hard	82.8%	Array Backtracking+2	Read
981. Time Based Key-Value Store	Medium	49.8%	Binary Search Design+2	Read
982. Triples with Bitwise AND Equal To Zero	Hard	60.1%	Array Bit Manipulation+1	Read
983. Minimum Cost For Tickets	Medium	67.4%	Array Dynamic Programming	Read
984. String Without AAA or BBB	Medium	45.6%	Greedy String	Read
985. Sum of Even Numbers After Queries	Medium	68.8%	Array Simulation	Read
986. Interval List Intersections	Medium	73.0%	Array Two Pointers	Read
987. Vertical Order Traversal of a Binary Tree	Hard	54.6%	Binary Tree Breadth-First Search+4	Read
988. Smallest String Starting From Leaf	Medium	61.2%	Backtracking Binary Tree+3	Read
989. Add to Array-Form of Integer	Easy	45.6%	Array Math	Read
990. Satisfiability of Equality Equations	Medium	52.2%	Array Graph+2	Read
991. Broken Calculator	Medium	56.0%	Greedy Math	Read
992. Subarrays with K Different Integers	Hard	69.0%	Array Counting+2	Read
993. Cousins in Binary Tree	Easy	59.8%	Binary Tree Breadth-First Search+2	Read
994. Rotting Oranges	Medium	59.5%	Array Breadth-First Search+1	Read
995. Minimum Number of K Consecutive Bit Flips	Hard	62.7%	Array Bit Manipulation+3	Read
996. Number of Squareful Arrays	Hard	51.9%	Array Backtracking+5	Read
997. Find the Town Judge	Easy	50.6%	Array Graph+1	Read
998. Maximum Binary Tree II	Medium	70.8%	Binary Tree Tree	Read
999. Available Captures for Rook	Easy	72.2%	Array Matrix+1	Read
1000. Minimum Cost to Merge Stones	Hard	47.0%	Array Dynamic Programming+1	Read

#951Medium

Flip Equivalent Binary Trees

Binary TreeDepth-First SearchTree

Acceptance: 69.8%

#952Hard

Largest Component Size by Common Factor

ArrayHash TableMath+2

Acceptance: 43.8%

#953Easy

Verifying an Alien Dictionary

ArrayHash TableString

Acceptance: 55.9%

#954Medium

Array of Doubled Pairs

ArrayGreedyHash Table+1

Acceptance: 39.7%

#955Medium

Delete Columns to Make Sorted II

ArrayGreedyString

Acceptance: 49.7%

#956Hard

Tallest Billboard

ArrayDynamic Programming

Acceptance: 52.0%

#957Medium

Prison Cells After N Days

ArrayBit ManipulationHash Table+1

Acceptance: 39.0%

#958Medium

Check Completeness of a Binary Tree

Binary TreeBreadth-First SearchTree

Acceptance: 59.0%

#959Medium

Regions Cut By Slashes

ArrayBreadth-First SearchDepth-First Search+3

Acceptance: 77.8%

#960Hard

Delete Columns to Make Sorted III

ArrayDynamic ProgrammingString

Acceptance: 72.7%

#961Easy

N-Repeated Element in Size 2N Array

ArrayHash Table

Acceptance: 79.9%

#962Medium

Maximum Width Ramp

ArrayMonotonic StackStack

Acceptance: 55.5%

#963Medium

Minimum Area Rectangle II

ArrayGeometryMath

Acceptance: 55.9%

#964Hard

Least Operators to Express Number

Dynamic ProgrammingMathMemoization

Acceptance: 48.3%

#965Easy

Univalued Binary Tree

Binary TreeBreadth-First SearchDepth-First Search+1

Acceptance: 72.9%

#966Medium

Vowel Spellchecker

ArrayHash TableString

Acceptance: 61.4%

#967Medium

Numbers With Same Consecutive Differences

BacktrackingBreadth-First Search

Acceptance: 59.1%

#968Hard

Binary Tree Cameras

Binary TreeDepth-First SearchDynamic Programming+1

Acceptance: 47.7%

#969Medium

Pancake Sorting

ArrayGreedySorting+1

Acceptance: 71.7%

#970Medium

Powerful Integers

EnumerationHash TableMath

Acceptance: 44.5%

#971Medium

Flip Binary Tree To Match Preorder Traversal

Binary TreeDepth-First SearchTree

Acceptance: 51.9%

#972Hard

Equal Rational Numbers

MathString

Acceptance: 46.7%

#973Medium

K Closest Points to Origin

ArrayDivide and ConquerGeometry+4

Acceptance: 69.4%

#974Medium

Subarray Sums Divisible by K

ArrayHash TablePrefix Sum

Acceptance: 56.7%

#975Hard

Odd Even Jump

ArrayDynamic ProgrammingMonotonic Stack+2

Acceptance: 41.1%

#976Easy

Largest Perimeter Triangle

ArrayGreedyMath+1

Acceptance: 62.1%

#977Easy

Squares of a Sorted Array

ArraySortingTwo Pointers

Acceptance: 73.7%

#978Medium

Longest Turbulent Subarray

ArrayDynamic ProgrammingSliding Window

Acceptance: 49.0%

#979Medium

Distribute Coins in Binary Tree

Binary TreeDepth-First SearchTree

Acceptance: 77.2%

#980Hard

Unique Paths III

ArrayBacktrackingBit Manipulation+1

Acceptance: 82.8%

#981Medium

Time Based Key-Value Store

Binary SearchDesignHash Table+1

Acceptance: 49.8%

#982Hard

Triples with Bitwise AND Equal To Zero

ArrayBit ManipulationHash Table

Acceptance: 60.1%

#983Medium

Minimum Cost For Tickets

ArrayDynamic Programming

Acceptance: 67.4%

#984Medium

String Without AAA or BBB

GreedyString

Acceptance: 45.6%

#985Medium

Sum of Even Numbers After Queries

ArraySimulation

Acceptance: 68.8%

#986Medium

Interval List Intersections

ArrayTwo Pointers

Acceptance: 73.0%

#987Hard

Vertical Order Traversal of a Binary Tree

Binary TreeBreadth-First SearchDepth-First Search+3

Acceptance: 54.6%

#988Medium

Smallest String Starting From Leaf

BacktrackingBinary TreeDepth-First Search+2

Acceptance: 61.2%

#989Easy

Add to Array-Form of Integer

ArrayMath

Acceptance: 45.6%

#990Medium

Satisfiability of Equality Equations

ArrayGraphString+1

Acceptance: 52.2%

#991Medium

Broken Calculator

GreedyMath

Acceptance: 56.0%

#992Hard

Subarrays with K Different Integers

ArrayCountingHash Table+1

Acceptance: 69.0%

#993Easy

Cousins in Binary Tree

Binary TreeBreadth-First SearchDepth-First Search+1

Acceptance: 59.8%

#994Medium

Rotting Oranges

ArrayBreadth-First SearchMatrix

Acceptance: 59.5%

#995Hard

Minimum Number of K Consecutive Bit Flips

ArrayBit ManipulationPrefix Sum+2

Acceptance: 62.7%

#996Hard

Number of Squareful Arrays

ArrayBacktrackingBit Manipulation+4

Acceptance: 51.9%

#997Easy

Find the Town Judge

ArrayGraphHash Table

Acceptance: 50.6%

#998Medium

Maximum Binary Tree II

Binary TreeTree

Acceptance: 70.8%

#999Easy

Available Captures for Rook

ArrayMatrixSimulation

Acceptance: 72.2%

#1000Hard

Minimum Cost to Merge Stones

ArrayDynamic ProgrammingPrefix Sum

Acceptance: 47.0%

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