Jubayer Nirjhor

January Lunchtime 2015

Piece of cake

February Challenge 2015

Chef and Chain, Chef and Equality

March Challenge 2015

Chef and Notebooks

June Challenge 2015

Chef and Memory Limit

August Challenge 2015

Cooking Machine

September Challenge 2015

Count Steps in Matrix

October Challenge 2015

Time measure, Count Subarrays, Who dares to be a millionaire, Spheres, Rupsa and Equilateral Triangle

November Challenge 2015

Eugene and function, Chef and cakes

December Challenge 2015

Chef and the stones, Plane Division, Oracle Devu and Longest Common Subsequence

June Cook-Off 2015

Strange operations

November Cook-Off 2015

Sereja and Line, Sereja and Array and Subtracting

December Cook-Off 2015

Chef and Subarrays

February Lunchtime 2015

Lucky Four

October Lunchtime 2015

emitL

December Lunchtime 2015

Distinct Codes

January Long Challenge 2016

Rupsa and the Game, Churu and Balls, Chef and Time Machine, Devu and Perfume

February Challenge 2016

Chef and Strange Operations, Devu and a light discussion, Chef-Detective

March Challenge 2016

Palindromic substrings, maximize the sum

April Challenge 2016

Help Watson Escape, Fibonacci Queries, Chef and Ballons, Devu and good strings, Chef And Magical Path, Chef And Coloring

May Challenge 2016

Chef and Balls, Forest Gathering, Chef and Big Soccer, Laddu

June Challenge 2016

Chef And The Hiring Event, Chef and Array and K, Chef And Binary Operation, Chef and Coins Game, Devu and an Array

July Challenge 2016

Andrash and Stipendium, Chef and Tetris, Chefland and Electricity

August Challenge 2016

Chef and Chocolate, Chef and Round Run

September Challenge 2016

Chef and Friends, Dividing Machine, Chef and Matrix Division, Chef and digits of a number, Faded Palindromes, JosephLand, Chef and calculation

October Challenge 2016

Sereja and Stones, Chef and Keyboard, Big Queries, Fenwick Iterations, Chef and Three Dogs, Power Sums, Chef and Two String

November Challenge 2016

Count Permutations, Friends Meeting, Urban Development, Gift and Chef, Chef and squares, Task for Alexey

December Challenge 2016

Train Partner, Kirito in labyrinth, Our Base is Under Attack

January Cook-Off 2016

Chef and Fruits

February Cook-Off 2016

Puppy and Catchers, Puppy and Board, Puppy and Sum

March Cook-Off 2016

Digital clock, Dual Nim, Alternating subarray prefix

April Cook-Off 2016

Movie Weekend, Odd Divisors, Queries on a Binary Tree

May Cook-Off 2016

Phantasialand

June Cook-Off 2016

Sticks, Right Triangle

October Cook-Off 2016

Sherlock and the Ugly Flower, Watson asks Does Permutation Exist, ChefWatson uses Social Network

November Cook-Off 2016

Sebi and the highway

February Lunchtime 2016

Chef and Socks, Chef and Tic-Tac-Toe

March Lunchtime 2016

Simple Statistics, ABABAABA

April Lunchtime 2016

Coins And Triangle

May Lunchtime 2016

Akhil Recovers The Lost Array, Akhil And Colored Balls, Akhil And Random String

June Lunchtime 2016

Collisions, One more weird game

July Lunchtime 2016

Drumpf for President!, Lumpy - The Bus Driver

September Lunchtime 2016

Chef and Inequality, Chef and Triangles

October Lunchtime 2016

The Largest Bouquet

January Challenge 2017

Digits Cannot Separate

February Challenge 2017

Eugene and big number, Chef and Triangles, Chef and his Best Friend, Chef and His Apartment Dues

April Challenge 2017

Chef and Digits, Bear and Random Grid, Chef and Divisor Tree, Stable market, Dish Of Life, Bear and Row 01, Bear and Clique Distances, Similar Dishes

May Challenge 2017

Chef and Sub Array , Chef and his daily routine, Courses in an university, Blocked websites, Median of adjacent maximum numbers, Chef and Subsequences

June Challenge 2017

Chef and Prime Queries, Euler Sum, A Good Set, Cloning, Chef and the Feast, Xenny and Coin Rankings, Triplets, Pairwise union of sets

July Challenge 2017

Chef and Sign Sequences, Pishty and tree, Tree Expectancy, Whats in the Name, Calculator , IPC Trainers

August Long Challenge 2017

Chef and Rainbow Array, Chef And Fibonacci Array, Chef and Mover, Palindromic Game, Greedy Candidates, Strings and Graphs

September Challenge 2017

Sereja and Commands, Chef and Pick Digit, Minimum Good Permutation, Weasel does Xor on Tree, Fill The Matrix, Little Chef and Sums

November Challenge 2017

Chef and Intersection Line, Product on the segment by modulo , Chef Hates Palindromes, Polynomials, Chef and Subarray Queries, Chef goes Left Right Left, Lovers Gift, Periodic Palindrome Construction, Villages and Tribes

March Cook-Off 2017

Rainbow Graph, Yet Another Card Game, Safe Robot

May Cook-Off 2017

La Liga, Balanced Array, Nasty Queries

June Cook-Off 2017

Ada and crayons, SnackUp, Centeroid

August Cook-Off 2017

Real obtuse, From heaven to earth

October Cook-Off 2017

Chef and Counting Test, Chef and Employment Test, Chef and Weird Queries

May Lunchtime 2017

Prefix Inversions

June Lunchtime 2017

Maximum Unique Segment, Two Numbers

February Challenge 2018

Chef And His Characters, Chef And The Patents, Permutation and Palindrome

February Cook-Off 2018

Chef and Cook-Off, Chef and Tuples, Chef and Chefness, Chef and Line

March Challenge 2018 DIV 1

Pishty and Triangles, Chef and Gcd Queries

June Cook-Off 2018 Division 1

Masha and Minions, Sonya and Segments, Good Permutations

December Cook-Off 2018 Division 1

Yalalovichik Numbers, Yalalovichik Strings

April Challenge 2018 Division 1

Vaibhav and Ministers, Cutting Plants, Highway Crossing, Chef and Same Old Recurrence, Count Good Prefixes

June Challenge 2018 Division 1

Two Flowers, Vision, Ways to Work, Expected Buildings, Archi and Tree

July Challenge 2018 Division 1

Pizza Delivery, Tom and Jerry, Reach Equilibrium, No Minimum No Maximum, Gears

August Challenge 2018 Division 1

Safe Partition

September Challenge 2018 Division 1

Bad Shuffle

August Lunchtime 2018 Division 1

Chef and Eid, Mix Mix Game

October Lunchtime 2018 Division 1

Robots Again, Coloring the Grid, Weird Question, Niceness of the Arrays

December Lunchtime 2018 Division 1

Choosing from Buckets, Drawing Lines, Maximize the NOSS, Age Calculator

January Challenge 2019 Division 1

Yet Another Problem About Sequences, Different Neighbours, Partition the Graph, Distinct Pairs, Party, A Pizza Slice

January Cook-Off 2019 Division 1

Ada School

January Lunchtime 2019 Division 1

Distances, Wanderer, Rooks

February Cook-Off 2019 Division 1

Max Range Queries, Chef and Secret Password, Chef in Evil Land, Chef and Party

March Challenge 2019 Division 1

Chef and Soccer, Cheating on Queue, Treasure Hunt

March Cook-Off 2019 Division 1

XOR N-bonacci Sequence, Points and Convex Hulls, Markers and Caps, Music Shopping

April Challenge 2019 Division 1

Offer for Chef, Kira Loves Palindromes, Mininum XOR over Tree, Playing with Numbers, Subtree Removal

April Cook-Off 2019 Division 1

Doubly Increasing Path, Random Game, Pied Piper vs Hooli, Mystery Tree

May Challenge 2019 Division 1

Trees and Degrees, Where to Build the Roads

May Cook-Off 2019 Division 1

Misha and Nice Sets, Bitsetbaba and Power Grid, Expected Xor, Searching for a Biclique

May Lunchtime 2019 Division 1 (Unrated)

Grid Tour, Reverse Maximisation, XOR Magic, Abdullah and Toll Discounts

June Challenge 2019 Division 1

Lent Money, Count Arrays, Chef and Ingredients, Chef and His Dish, Intersecting Paths, Sum and GCD

June Lunchtime 2019 Division 1

The Grux Permutation , Gii and His Club, Igzi and Burly Array, Ivan Pesic and His World Tour

August Lunchtime 2019 Division 1

Equal Average, Destroy Cells, Chef Does Coke Yet Again

September Challenge 2019 Division 1

Expected GCD, Doofish Set, Power Sum

October Challenge 2019 Division 1

Even Edges, Bacterial Reproduction, Chef and Maximum Star Value, Array Modification

November Challenge 2019 Division 1

Physical Exercise, Smallest Beautiful Number, From Zero to Infinity, Single Point of Failure, Winning Ways

December Challenge 2019 Division 1

Chefina and Ranges, Binary XOR, Binomial Fever, Scoring Pairs, Sticky Notes, Test Generation, Addition

March Challenge 2020 Division 1

Winning Ways 2

April Challenge 2020 Division 1

Strange Number, Squared Subsequences, Perfect Power Divisors, Ready Bitwise, Factor Tree, Leaked Answers (Challenge)

May Challenge 2020 Division 1

Buying a New String, Triple Sort, Binary Land, Sorting Vases, Not a Real World Problem, Chef and Rainbow Road, Chef and Bitwise Product

March Cook-Off 2020 Division 1

Mysterious Sequence, A Tree to Remember, Maximize Letter Beauty, Random Chocolates, Escape the Tree

April Cook-Off 2020 Division 1

The Gifting Problem, Inversions in Permutations

March Lunchtime 2020 Division 1 (Unrated)

Maximize LCM, Strip in a Tree!

June Challenge 2020 Division 1

The Tom and Jerry Game!, Perfect Partitions

July Challenge 2020 Division 1

LCM Constraints, Chefina and Swaps, Easy Geo xD, Chef and Dragon Dens, Missing a Point, Doctor Chef, Weird Product, Expected Repetitions, Expected Spanning Trees

August Challenge 2020 Division 1

Insanely Hard School Exams, Subsequence Frequency Counting, Precious Stones , Chefina and Strange Tree, Smallest KMP, Chef Thanos Wants Perfect Balance, Chef and Wedding Arrangements

September Challenge 2020 Division 1

Chefina and Swap, Chef and Trump Cards, Find XOR, Rotate the Polyline, Ada Matrix

July Cook-Off 2020 Division 1

What Is This, a Crossover Episode, The In-XOR-able Task, Even-tual Reduction, OR-thodox Distinction, Path-etic Products

July Lunchtime 2020 Division 1

Golomb Sequence, Coloured Pairings, Binary Concatenation

October Challenge 2020 Division 1

Inversions, Positive AND, Replace for X, Compress all Subsegments, Adding Squares

November Challenge 2020 Division 1

Panic! at the Disco, Chef and the Combination Lock, Restore Sequence, Magical Candy Store, Red-Black Boolean Expression, Scalar Product Tree, Unusual Queries

December Challenge 2020 Division 1

Hail XOR, Square Root of LCA Convolution, Calculus, Permutations, String Operations, Positive Prefixes, Even Pair Sum

December Cook-Off 2020 Division 1

Self-Destructing Strings, Sed Passwords, Circle of Chaos, Carry All Fruits

December Lunchtime 2020 Division 1 (Unrated)

K-Tuple Tree, Even Sequence, Three Letters, One Zero Swaps

January Lunchtime 2021 Division 1 (Unrated)

Good Grid, Dreams of Divisibility, Even Sum

October Cook-Off 2020 Division 1

Path-etic Sums, An Inveractive Problem, The In-XOR-able Task, Yet Another Crossover Episode

November Cook-Off 2020 Division 1

Flip the String, Chef and IPC Certificates, Communication Channel, Hiring Workers

October Lunchtime 2020 Division 1

Chef Likes Good Sequences, Chef Is Just Throwing Random Words, Counting Spaghetti, Cute Chef Gift

November Lunchtime 2020 Division 1

Gasoline, Rook Path, Fractions

Coders' Legacy (Rated for all)

Chef vs Doof, Doof on Cartesian, Doof fires Brackets, Jeremy gets a gift

September Cook-Off 2020 Division 1

Joined Subarrays on Tree, Maximise Subsequence Value, Minimum Insertions

February Challenge 2021 Division 1

Team Name, Another Tree with Number Theory, Prime Game, XOR Sums

February Lunchtime 2021 Division 1

Average Sorting, Sed Max, Chef and Reordering, Independent Set

March Lunchtime 2021 Division 1

Uniform, Lunchtime, Gamer

April Cook-Off 2021 Division 1

Array and Operations, Tree Distances, OR of ANDs, Valet Parking

April Lunchtime 2021 Division 1

A Special Tree

May Lunchtime 2021 Division 1

Total Components, K-Subarrays

June Challenge 2021 Division 1 (Unrated)

Minimum Dual Area, Bitwise Tuples, Maximum Frequent Subarray Sum, MathBuzz, Minimum Subtree Cover

June Lunchtime 2021 Division 1

Richie Rich

July Challenge 2021 Division 1 (Unrated)

Even Odd Partition, Chef and Pairs

July Cook-Off 2021 Division 1

Beautiful Subsequence, Mod Equality, Hidden Colored Graph

July Lunchtime 2021 Division 1

Xor Separation, Longest Good Segment

August Lunchtime 2021 Division 1

Bunny Hops, Just a Graph, Longest Spanning Substrings, Chef and Deque

SnackDown 2021 - Online Qualifiers

Prefix as a Substring 2, Lucky Number, Maximum Number Of Distinct Elements, Minimise Difference

SnackDown 2021 - Online Round 1A

Yet Another Flipping Problem, Round Robin Ranks , Dance Moves, Equal Beauty, Min Max LCM

SnackDown 2021 - Online Pre-Elimination

Non-Decreasing Subsequence of size K, Product Pain, Guests like slippers

SnackDown 2021 - Online Elimination Round (Rated for all)

Random Convex Hull, Graduate Work Matters, Sorting Segments

November Lunchtime 2021 Division 1

Permutation Pairs, Subarray Jumps

December Cook-Off 2021 Division 1

Binary String Game, RGB Construction

December Lunchtime 2021 Division 1

Optimal Sorting, Romantic Reversals, Sleep Technique , Point constraints

February Cook-Off 2022 Division 1

Xor Becoming Uncanny, Perfect Permutation, PerMEXuation , Mango Market

March Lunchtime 2022 Division 1

Subsequence, Mathology, Winter, Adjacency Love

April Long One 2022 Division 1 (Unrated)

Yet Another Mex Problem

April Lunchtime 2022 Division 1(Rated)

Do Not Touch the MEX!!!, Secret Machine Mania, AND Palindromes

May Cook-Off 2022 Division 1 (Rated)

Different Subarrays Rearrange, Triple Inversions

Starters 40 Division 1 (Unrated)

The Three Bogatyrs, Max Value of MST, Or Permutation, Good Pairs

July Cook-Off 2022 Division 1 (Rated)

Segmentation Fault, Subsequence LCM

June Cook-Off 2022 Division 1 (Rated)

Throw and Take, Simple XOR, Prefix Suffix Distinct, Split AND Sum

June Long One 2022 Division 1 (Unrated)

Add By Permutation

June Lunchtime 2022 Division 1 (Rated)

The Lost Array, Max Shift After XOR, XOR Times 2 Is Sum, Minimum Xor On Segment, XOR, The Detective

Starters 51 Division 1 (Unrated)

Chef & Cook Game, Differentiation, Prefix Suffix And Or

Starters 52 Division 1 (Unrated)

Flipping Failure, Nil Xor

September Long 2022 Division 1 (Unrated)

Alone Alice!

Starters 71 Division 1 (Unrated)

Pet Store, Flip the Prefix, Unique Mode, Instagram, Snapchat, Expected Sum, Perfect Trio, Maximizing LCS

Starters 72 Division 1 (Rated till 5-Stars)

Indivisible, Apples and oranges, N Triplets, Sum it

Starters 86 Division 1 (Rated for All)

Least Size, Minimum Operation, String Game , Largest Y

Starters 87 Division 1 (Rated till 6 Stars)

Count the Permutations (always), Inversions of subsequences, AB plus C, One or All

Starters 88 Division 1 (Rated till 6 Stars)

Maximum And Or, Chef and Asteroids, Good Operations, Minimize the Bits, Chef and Good Array, Minimum OR Spanning Tree

Starters 89 Division 1 (Rated till 5 Stars)

Positive or Negative Subarrays, Subarray Removal, Two Averages, Restore Communication, Tree Queries, Evil Infection

Starters 90 Division 1 (Rated till 6 Stars)

Crushed Apples and a Balance Scale, Minimum Ugliness, Sum of Goodness, Printing Binary Array, Anti Palindrome

Starters 91 Division 1 (Rated till 6 Stars)

Cheapest Office, Odd GCD Permutation, Chef Odd, Maximum Sum Permutation

Starters 92 Division 1 (Rated till 6 Stars)

Rectangular Tiling, Dividing into Groups, Beautification of array, Distance Coloring

Starters 93 Division 1 (Rated for All)

Thank U, Next, Why Try, NASA, Greedy, Bloodline, Motive

Starters 95 Division 1 (Rated till 6 Stars)

Guess Game, Chef and Moves of GCD, Partition and Maximize, Boxes, Transfusion Chain, Break This Array

Starters 96 Division 1 (Rated till 5 Stars)

Swap the numbers, Mex Array, Absolute Differences

Starters 97 Division 1 (Rated till 6 Stars)

Make It Special, Unreachability Cost, No Palindrome, Triplets Min

Starters 99 Division 1 (Rated till 6 Stars)

Segment Three, Musical Chairs, Two Piles, Yet Another Bitwise Problem, Exclusion-Inclusion

Starters 100 Division 1 (Rated)

Prime Permutation, Stamps 100, Concussive Sequence, Combinatorics Is Fun, Ant

Starters 102 Division 1 (Rated till 6 Stars)

Chess ELO, Parity Permutation, Light The Bulb, Chef Segment, Bit Play

Starters 103 Division 1 (Rated till 6 Stars)

Squarified, Chandelier, Unique xor, Divisible By 8

Starters 104 Division 1 (Rated till 6 Stars)

Find Diameter, Combinatorics Is Fun, Longest Non Decreasing Subsequence, Lexicographically Largest , Construct An Array, Maximise Sum

Starters 105 Division 1 (Rated till 6 Stars)

Ghoul-icious Goodies, Racing Dead, Spooky Sequences, Dull Operation, Wishcraft

Starters 106 Division 1 (Rated till 5 Stars)

Playing with OR, Save People, Guess the winner!, Count Possibilities, Smallest Excluded LCM, Reach Anywhere, Summing the values, Is it Obvious

August Long 2023 Division 1 (Unrated)

Spiritual Chef

Starters 111 Division 1 (Rated till 6 Stars)

LCM Mania, Prefixing, Prime Range Game, Beautiful Strings, ODI Cricket, Component Count, Square Count

Starters 112 Divison 1 (Rated till 6 Stars)

Cursed Indices, Yet Another Array Game, Subtree Coloring, Permutation Construction

Starters 113 Division 1 (Rated)

Count Distinct Arrays, Counting Is Fun, Maximise The Minimum, Minimise Maximum Subarray Sum, Make All Equal, Score Sum, Maximum Score

Starters 115 Division 1 (Rated)

Delete The Array, Subtraction Sequence I, Subtraction Sequence II, Greedy LIS Algorithm, Binary Grid Forces, Make All Zero

Starters 116 Divison 1 (Rated till 6-Stars)

Chef Product, ORST , Permutation Sort, Exact Savings

Starters 125 Division 1 (Rated till 6-Stars)

Bucket Game, Operating on A, Binary Minimal

Starters 126 Division 1 (Rated till 6 Stars)

Tree Distance Set, Freedom, Uncommon Cycles, LCD, Triangular Swaps

Starters 133 Division 1 (Rated till 6-Star)

ABC Conjecture 3, Powered Parameters, Too Far For Comfort, Fireworks, Too Far For Comfort (Easy Version)

Starters 135 Division 1 (Rated till 5-Stars)

Milky-Dark Chocolates, Graph Cost, Limit of MEX, Change A to B

Starters 136 Division 1 ( Rated till 6-Stars )

Game On Rectangle, Lexicographically Maximal Prefix AND, Sum of Max K Subarray, Minimum Segments, Sum of Modes

Starters 137 Division 1 (Rated till 5-Stars)

Unusual Queries

Starters 138 Division 1 (Rated till 6-Stars)

A power B mod C , TRIPLE PRIMES, Prefix Suffix Inequality, Distinct Substring

Starters 140 Division 1 (Rated till 5-Stars)

Lucky Matrix, Split Permutation, Trick Or Treat, Break The String, Tree Removal

Starters 141 Division 1 (Rated till 5-Stars)

Possible Contender, Amphibian Escape, Perfect Prefixes

Starters 142 Division 1 (Rated till 5-Stars)

Sum of Xors, Pairs Sum with Length x, The Cards Machine, Array Removal, Number Hunt

Starters 143 Division 1 (Rated till 5-Stars)

Non-Divisor Array, Max Min and Length

Starters 145 Division 1 (Rated till 6-Stars)

Beautiful Array, Make Bob Win , Querified, Square String

Starters 146 Division 1 (Rated till 5 stars)

Back Front, Connect The Chains, Bouncing Ball, Permutation Construction, Binary Strings Yet Again

Starters 147 Division 1 (Rated till 5 stars)

Counting Triangles 101, K Subsequence 101, Truth Teller And Liars 101, Independence Day 101, Non-Primes 101, Gold Coins 101

Starters 153 (Rated till 5 stars)

Another Game, Colorful Tree (Easy Version), Xometry (Easy Version)

Starters 161 (Rated)

Min-Max Game, Red-Blue Sort, One To Three, Quick Exit

Starters 162 (Rated till 5 stars)

Empty the String, MEX of XOR, Permutation Mod K

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