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
3986. Number of Elapsed Seconds Between Two Times	Easy	82.5%	Math String	Read
3982. Sum of Integers with Maximum Digit Range	Easy	72.9%	Array Math	Read
3992. Rearrange String to Avoid Character Pair	Easy	77.8%	Sorting String+1	Read
3978. Unique Middle Element	Easy	72.3%	Array Counting	Read
3987. Minimum Total Cost to Process All Elements	Medium	24.7%	Array Math+1	Read
3990. Create Grid With Exactly K Paths II	Hard	73.8%		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
3989. Maximum Consistent Columns in a Grid	Hard	68.7%	Array Dynamic Programming+1	Read
3984. Divisible Game	Medium	42.3%	Array Dynamic Programming+3	Read
3991. Sort Array Using Prefix Reversals	Medium	70.8%		Read
3995. Minimum Cost to Convert String III	Hard	55.6%	Array Dynamic Programming+1	Read
3981. Count Distinct Ways to Form Target from Two Strings	Hard	46.4%	Dynamic Programming Prefix Sum+1	Read
3985. Palindromic Subarray Sum	Hard	34.0%	Array Binary Search+2	Read
3998. Transform Binary String Using Subsequence Sort	Medium	37.9%	Array Greedy+2	Read
3999. Minimum Number of String Groups Through Transformations	Hard	47.9%	Hash Table String+1	Read
4000. Largest Integer With Given Digit Sum	Easy	61.0%	Greedy Math	Read
4002. Count Valid Sequences	Medium	42.5%	Combinatorics Math	Read
4001. Aggregate Two Time Series	Medium	57.9%	Array Two Pointers	Read
4003. Minimum Cost Path with Alternating Directions III	Hard	61.4%	Array Graph+3	Read
4005. Minimum Operations to Make Array Equal III	Hard	26.3%		Read
4004. Minimum Moves to Balance Circular Array II	Hard	61.8%		Read
4006. Count Valid Prefixes	Easy	78.0%	Counting String	Read
4007. Widest Possible Fence	Hard	16.9%	Array Counting+2	Read
4008. Minimum Initial Strength to Defeat All Monsters	Medium	50.1%	Array Binary Search+2	Read
4009. Minimum Possible Maximum Waiting Time	Hard	29.3%	Array Dynamic Programming+1	Read
4010. Maximize Pair Strength Using GCD	Easy	48.6%	Array Enumeration+2	Read
4013. Count Subarrays With Even Odd Ratio II	Hard	40.3%	Array Binary Indexed Tree+4	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
4017. Peaks in Array II	Hard	27.8%	Array Divide and Conquer+1	Read
4018. Total Sum of Interaction Cost in Tree Groups II	Hard	69.2%		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
4023. Elevator Requests II	Hard	27.0%	Array Dynamic Programming+1	Read
4020. Elevator Requests I	Easy	84.1%	Array Simulation	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
4027. Elevator Requests III	Hard	45.7%	Array Bit Manipulation+3	Read
4024. Nearest Available Drone	Easy	66.8%	Array Enumeration	Read
4025. Minimize the Maximum Waiting Time at Synchronized Traffic Lights	Medium	64.7%	Array Greedy	Read
4029. Minimum Operations to Make a Rotated Palindrome II	Hard	62.9%		Read
4026. Maximum Gap Between Stations	Medium	52.4%	Greedy String+1	Read
4030. Elevator Requests IV	Easy	60.0%		Read
4028. Minimum Operations to Make a Rotated Palindrome II	Hard	68.4%		Read

#3986Easy

Number of Elapsed Seconds Between Two Times

MathString

Acceptance: 82.5%

#3982Easy

Sum of Integers with Maximum Digit Range

ArrayMath

Acceptance: 72.9%

#3992Easy

Rearrange String to Avoid Character Pair

SortingStringTwo Pointers

Acceptance: 77.8%

#3978Easy

Unique Middle Element

ArrayCounting

Acceptance: 72.3%

#3987Medium

Minimum Total Cost to Process All Elements

ArrayMathSimulation

Acceptance: 24.7%

#3990Hard

Create Grid With Exactly K Paths II

Acceptance: 73.8%

#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%

#3989Hard

Maximum Consistent Columns in a Grid

ArrayDynamic ProgrammingMatrix

Acceptance: 68.7%

#3984Medium

Divisible Game

ArrayDynamic ProgrammingEnumeration+2

Acceptance: 42.3%

#3991Medium

Sort Array Using Prefix Reversals

Acceptance: 70.8%

#3995Hard

Minimum Cost to Convert String III

ArrayDynamic ProgrammingString

Acceptance: 55.6%

#3981Hard

Count Distinct Ways to Form Target from Two Strings

Dynamic ProgrammingPrefix SumString

Acceptance: 46.4%

#3985Hard

Palindromic Subarray Sum

ArrayBinary SearchHash Function+1

Acceptance: 34.0%

#3998Medium

Transform Binary String Using Subsequence Sort

ArrayGreedyString+1

Acceptance: 37.9%

#3999Hard

Minimum Number of String Groups Through Transformations

Hash TableStringTwo Pointers

Acceptance: 47.9%

#4000Easy

Largest Integer With Given Digit Sum

GreedyMath

Acceptance: 61.0%

#4002Medium

Count Valid Sequences

CombinatoricsMath

Acceptance: 42.5%

#4001Medium

Aggregate Two Time Series

ArrayTwo Pointers

Acceptance: 57.9%

#4003Hard

Minimum Cost Path with Alternating Directions III

ArrayGraphHeap (Priority Queue)+2

Acceptance: 61.4%

#4005Hard

Minimum Operations to Make Array Equal III

Acceptance: 26.3%

#4004Hard

Minimum Moves to Balance Circular Array II

Acceptance: 61.8%

#4006Easy

Count Valid Prefixes

CountingString

Acceptance: 78.0%

#4007Hard

Widest Possible Fence

ArrayCountingEnumeration+1

Acceptance: 16.9%

#4008Medium

Minimum Initial Strength to Defeat All Monsters

ArrayBinary SearchGreedy+1

Acceptance: 50.1%

#4009Hard

Minimum Possible Maximum Waiting Time

ArrayDynamic ProgrammingMemoization

Acceptance: 29.3%

#4010Easy

Maximize Pair Strength Using GCD

ArrayEnumerationMath+1

Acceptance: 48.6%

#4013Hard

Count Subarrays With Even Odd Ratio II

ArrayBinary Indexed TreeDivide and Conquer+3

Acceptance: 40.3%

#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%

#4017Hard

Peaks in Array II

ArrayDivide and ConquerSegment Tree

Acceptance: 27.8%

#4018Hard

Total Sum of Interaction Cost in Tree Groups II

Acceptance: 69.2%

#4016Medium

Maximum Area of Two Non-Overlapping Square Submatrices

ArrayBinary SearchDynamic Programming+1

Acceptance: 40.9%

#4019Medium

Merge Close Characters II

Acceptance: 77.4%

#4023Hard

Elevator Requests II

ArrayDynamic ProgrammingSorting

Acceptance: 27.0%

#4020Easy

Elevator Requests I

ArraySimulation

Acceptance: 84.1%

#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%

#4027Hard

Elevator Requests III

ArrayBit ManipulationBitmask+2

Acceptance: 45.7%

#4024Easy

Nearest Available Drone

ArrayEnumeration

Acceptance: 66.8%

#4025Medium

Minimize the Maximum Waiting Time at Synchronized Traffic Lights

ArrayGreedy

Acceptance: 64.7%

#4029Hard

Minimum Operations to Make a Rotated Palindrome II

Acceptance: 62.9%

#4026Medium

Maximum Gap Between Stations

GreedyStringTwo Pointers

Acceptance: 52.4%

#4030Easy

Elevator Requests IV

Acceptance: 60.0%

#4028Hard

Minimum Operations to Make a Rotated Palindrome II

Acceptance: 68.4%

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