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
3955. Valid Binary Strings With Cost Limit	Medium	78.5%	Backtracking Bit Manipulation+2	Read
3952. Maximum Total Value of Covered Indices	Medium	28.5%	Array Dynamic Programming+2	Read
3958. Minimum Cost to Split into Ones II	Medium	68.4%		Read
3960. Frequency Balance Subarray	Medium	29.5%	Array Counting+1	Read
3961. Maximize Sum of Device Ratings	Medium	39.4%	Array Greedy+2	Read
3968. Maximum Manhattan Distance After All Moves	Medium	63.3%	Counting Math+1	Read
3964. Minimum Lights to Illuminate a Road	Medium	37.8%	Array Prefix Sum	Read
3969. Valid Subarrays With Matching Sum Digits I	Medium	46.8%	Array Enumeration+3	Read
3970. Shortest Path With At Most K Consecutive Identical Characters	Medium	44.7%	Graph Heap (Priority Queue)+2	Read
3965. Finish Time of Tasks I	Medium	60.3%	Array Depth-First Search+2	Read
3974. Maximum Total Sum of K Selected Elements	Medium	49.1%	Array Greedy+1	Read
3976. Maximum Subarray Sum After Multiplier	Medium	25.9%	Array Dynamic Programming	Read
3975. Filter Occupied Intervals	Medium	46.0%	Array Sorting	Read
3993. Maximum Value of an Alternating Sequence	Medium	31.5%	Greedy Math	Read
3997. Count Dominant Nodes in a Binary Tree	Medium	72.1%	Binary Tree Depth-First Search+1	Read
3987. Minimum Total Cost to Process All Elements	Medium	24.7%	Array Math+1	Read
3983. Subsequence After One Replacement	Medium	21.6%	String Two Pointers	Read
3988. Create Grid With Exactly K Paths I	Medium	33.1%	Array Combinatorics+2	Read
3979. Maximum Valid Pair Sum	Medium	49.2%	Array Enumeration	Read
3994. Minimum Adjacent Swaps to Partition Array	Medium	57.4%	Array Greedy	Read
3980. Minimum Operations to Transform Binary String	Medium	36.4%	Dynamic Programming Greedy+1	Read
3984. Divisible Game	Medium	42.3%	Array Dynamic Programming+3	Read
3991. Sort Array Using Prefix Reversals	Medium	70.8%		Read
3998. Transform Binary String Using Subsequence Sort	Medium	37.9%	Array Greedy+2	Read
4002. Count Valid Sequences	Medium	42.5%	Combinatorics Math	Read
4001. Aggregate Two Time Series	Medium	57.9%	Array Two Pointers	Read
4008. Minimum Initial Strength to Defeat All Monsters	Medium	50.1%	Array Binary Search+2	Read
4011. Count Subarrays With Even Odd Ratio I	Medium	60.6%	Array Binary Indexed Tree+4	Read
4012. Count of Unfinished Tasks After Each Shift	Medium	41.9%	Array Binary Search+1	Read
4014. Minimum Total Price After Applying Discounts	Medium	71.8%	Array Greedy+2	Read
4015. Weighted Sum of a Tree	Medium	41.7%	Array Depth-First Search+1	Read
4016. Maximum Area of Two Non-Overlapping Square Submatrices	Medium	40.9%	Array Binary Search+2	Read
4019. Merge Close Characters II	Medium	77.4%		Read
4021. Minimum Operations to Make a Rotated Palindrome I	Medium	63.9%	Enumeration Math+1	Read
4022. K-th Digit in Infinite String	Medium	35.1%	Binary Search Math	Read
4025. Minimize the Maximum Waiting Time at Synchronized Traffic Lights	Medium	64.7%	Array Greedy	Read
4026. Maximum Gap Between Stations	Medium	52.4%	Greedy String+1	Read
4031. Find All Numbers Disappeared in an Array II	Medium	52.8%	Array Binary Search+1	Read
4032. Longest Subarray With at Most K Distinct Prime Factors	Medium	56.5%	Array Hash Table+3	Read
4034. Minimum Bishop Moves to Reach Target	Medium	65.4%	Array Math	Read
4035. Maximum Valid Split Positions I	Medium	51.8%	Array Enumeration+2	Read
4036. Lexicographically Largest String After Pair Transformations	Medium	42.2%	Array Bit Manipulation+2	Read
4039. Sum of Decoded Numbers	Medium	44.8%	Array Math+1	Read
4040. Minimum Operations to Form Subset Sum I	Medium	52.4%	Array Dynamic Programming	Read
4044. Count Good Cyclic Rotations	Medium	49.0%	Array Prefix Sum+1	Read
4045. Count Robot Groups	Medium	31.3%	Array Monotonic Stack+1	Read
4049. Count Values With Equally Spaced Occurrences II	Medium	62.9%	Array Hash Table	Read
4050. Minimum Days to Score Exactly N Points	Medium	41.6%	Dynamic Programming Math	Read
4053. Minimum Operations to Make Every Element Palindromic	Medium	14.9%	Array Binary Search	Read
4054. Count Shadow Pairs I	Medium	41.2%	Array Monotonic Stack+1	Read

#3955Medium

Valid Binary Strings With Cost Limit

BacktrackingBit ManipulationEnumeration+1

Acceptance: 78.5%

#3952Medium

Maximum Total Value of Covered Indices

ArrayDynamic ProgrammingGreedy+1

Acceptance: 28.5%

#3958Medium

Minimum Cost to Split into Ones II

Acceptance: 68.4%

#3960Medium

Frequency Balance Subarray

ArrayCountingHash Table

Acceptance: 29.5%

#3961Medium

Maximize Sum of Device Ratings

ArrayGreedyMatrix+1

Acceptance: 39.4%

#3968Medium

Maximum Manhattan Distance After All Moves

CountingMathString

Acceptance: 63.3%

#3964Medium

Minimum Lights to Illuminate a Road

ArrayPrefix Sum

Acceptance: 37.8%

#3969Medium

Valid Subarrays With Matching Sum Digits I

ArrayEnumerationHash Table+2

Acceptance: 46.8%

#3970Medium

Shortest Path With At Most K Consecutive Identical Characters

GraphHeap (Priority Queue)Shortest Path+1

Acceptance: 44.7%

#3965Medium

Finish Time of Tasks I

ArrayDepth-First SearchDynamic Programming+1

Acceptance: 60.3%

#3974Medium

Maximum Total Sum of K Selected Elements

ArrayGreedySorting

Acceptance: 49.1%

#3976Medium

Maximum Subarray Sum After Multiplier

ArrayDynamic Programming

Acceptance: 25.9%

#3975Medium

Filter Occupied Intervals

ArraySorting

Acceptance: 46.0%

#3993Medium

Maximum Value of an Alternating Sequence

GreedyMath

Acceptance: 31.5%

#3997Medium

Count Dominant Nodes in a Binary Tree

Binary TreeDepth-First SearchTree

Acceptance: 72.1%

#3987Medium

Minimum Total Cost to Process All Elements

ArrayMathSimulation

Acceptance: 24.7%

#3983Medium

Subsequence After One Replacement

StringTwo Pointers

Acceptance: 21.6%

#3988Medium

Create Grid With Exactly K Paths I

ArrayCombinatoricsMath+1

Acceptance: 33.1%

#3979Medium

Maximum Valid Pair Sum

ArrayEnumeration

Acceptance: 49.2%

#3994Medium

Minimum Adjacent Swaps to Partition Array

ArrayGreedy

Acceptance: 57.4%

#3980Medium

Minimum Operations to Transform Binary String

Dynamic ProgrammingGreedyString

Acceptance: 36.4%

#3984Medium

Divisible Game

ArrayDynamic ProgrammingEnumeration+2

Acceptance: 42.3%

#3991Medium

Sort Array Using Prefix Reversals

Acceptance: 70.8%

#3998Medium

Transform Binary String Using Subsequence Sort

ArrayGreedyString+1

Acceptance: 37.9%

#4002Medium

Count Valid Sequences

CombinatoricsMath

Acceptance: 42.5%

#4001Medium

Aggregate Two Time Series

ArrayTwo Pointers

Acceptance: 57.9%

#4008Medium

Minimum Initial Strength to Defeat All Monsters

ArrayBinary SearchGreedy+1

Acceptance: 50.1%

#4011Medium

Count Subarrays With Even Odd Ratio I

ArrayBinary Indexed TreeDivide and Conquer+3

Acceptance: 60.6%

#4012Medium

Count of Unfinished Tasks After Each Shift

ArrayBinary SearchPrefix Sum

Acceptance: 41.9%

#4014Medium

Minimum Total Price After Applying Discounts

ArrayGreedySorting+1

Acceptance: 71.8%

#4015Medium

Weighted Sum of a Tree

ArrayDepth-First SearchTree

Acceptance: 41.7%

#4016Medium

Maximum Area of Two Non-Overlapping Square Submatrices

ArrayBinary SearchDynamic Programming+1

Acceptance: 40.9%

#4019Medium

Merge Close Characters II

Acceptance: 77.4%

#4021Medium

Minimum Operations to Make a Rotated Palindrome I

EnumerationMathString

Acceptance: 63.9%

#4022Medium

K-th Digit in Infinite String

Binary SearchMath

Acceptance: 35.1%

#4025Medium

Minimize the Maximum Waiting Time at Synchronized Traffic Lights

ArrayGreedy

Acceptance: 64.7%

#4026Medium

Maximum Gap Between Stations

GreedyStringTwo Pointers

Acceptance: 52.4%

#4031Medium

Find All Numbers Disappeared in an Array II

ArrayBinary SearchSorting

Acceptance: 52.8%

#4032Medium

Longest Subarray With at Most K Distinct Prime Factors

ArrayHash TableMath+2

Acceptance: 56.5%

#4034Medium

Minimum Bishop Moves to Reach Target

ArrayMath

Acceptance: 65.4%

#4035Medium

Maximum Valid Split Positions I

ArrayEnumerationMath+1

Acceptance: 51.8%

#4036Medium

Lexicographically Largest String After Pair Transformations

ArrayBit ManipulationGreedy+1

Acceptance: 42.2%

#4039Medium

Sum of Decoded Numbers

ArrayMathSimulation

Acceptance: 44.8%

#4040Medium

Minimum Operations to Form Subset Sum I

ArrayDynamic Programming

Acceptance: 52.4%

#4044Medium

Count Good Cyclic Rotations

ArrayPrefix SumSliding Window

Acceptance: 49.0%

#4045Medium

Count Robot Groups

ArrayMonotonic StackStack

Acceptance: 31.3%

#4049Medium

Count Values With Equally Spaced Occurrences II

ArrayHash Table

Acceptance: 62.9%

#4050Medium

Minimum Days to Score Exactly N Points

Dynamic ProgrammingMath

Acceptance: 41.6%

#4053Medium

Minimum Operations to Make Every Element Palindromic

ArrayBinary Search

Acceptance: 14.9%

#4054Medium

Count Shadow Pairs I

ArrayMonotonic StackStack

Acceptance: 41.2%

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