Python Practice Problems

Python (415)

• Above the Title - medium - Some names carry a genre. Total the box office behind them.
• Absent Without Leave - medium - Between the first name and the last, the ones who never showed. Account for them.
• Against the Current - hard - Too big to load. Read what you can.
• Against the Grain - medium - Turn the grid on its side and let every column stand up as a row.
• All the Way Down - medium - However deep it nests, every leaf belongs on one line.
• All Told - easy - Every shift leaves a number behind. Total the fleet.
• Back to Back - medium - Windows stacked on windows. Find the real spans.
• Batch Records - medium - Too many at once. Break them into groups.
• Between the Clicks - medium - Clicks arrive scrambled. Find where one visit ends and the next begins.
• Between the Pings - medium - The fleet never stops talking. Find where each vehicle paused.
• Birds of a Feather - medium - Every record finds its kin; keep them in the order they arrived.
• By What They Answer To - medium - Every name reports to its first letter. Sort the roll call as it comes in.
• Caesar Shift Check - easy - The key turns. Does it open?
• Carrying Forward - medium - The total grows with every row.
• Carry the One - medium - In grade-school subtraction you scribble a mark each time you borrow. Recover those marks.
• Char Profile - medium - Every character in the string tells a story.
• Closing Bell - medium - Every share you own, priced at today's close. Tally the gains.
• Closing Time - easy - Every bracket you open is a promise. Check that the parser keeps all of them.
• Column Range - easy - From minimum to maximum. What is the spread?
• Corner to Corner - medium - A grid pressed flat still remembers its corners.
• Detect Outliers - medium - Most values are normal. Some are suspicious.
• Dice Roll Scoring - medium - The pattern rewards the patient.
• Dictionary Key Intersection - medium - Two dictionaries. What do they share?
• Dominant Element - easy - Majority element. Appears more than half the time.
• Double Duty - medium - Split the money. Some wore two hats.
• Downstream - hard - Nothing runs until what it needs has run.
• Down the Line - medium - Load has to keep moving. Pass it down the line.
• Even Filter - easy - Only the even ones survive.
• Every Line on the Receipt - medium - Nested deep inside the receipt. Pull every item out.
• Everything Beneath - medium - Every account carries the weight of all it contains.
• Everything That Repeats - easy - Say it once, then say how many times it stayed.
• Every Trace - medium - It is in there somewhere. Where exactly?
• Execution Timer Wrapper - medium - Function wrapped with a timer. Duration captured on exit.
• Explode List - easy - One row holds many values. Unpack it.
• Extract Domain - easy - The domain is buried in the string.
• Extract Leaf Values - medium - The tree has leaves. Pluck them.
• Faces in the Crowd - medium - New arrivals keep showing up. Count the ones you have not seen yet.
• Familiar Ground - medium - Keep walking. Sooner or later you may recognize where you're standing.
• Find Mode - medium - One value appears more than the rest.
• Footprints in the Feed - medium - Every trade left a footprint.
• Full Circle - medium - Follow the chain long enough and it might loop back.
• Greeting Formatter Class - easy - First impressions are formatted carefully.
• Group Average - hard - Same group, different values. What is typical?
• Hands Apart - easy - Two hands. One gap. One number.
• Hidden Depths - medium - Each dot marks a level. Rebuild the tree it stands for.
• Higher Ground - medium - Somewhere the ground stops climbing.
• High Water - easy - Every reading remembers the highest that came before.
• High Water Mark - easy - Even below zero, one reading still stands above the rest.
• Holding the Center - hard - The middle value keeps moving as new data arrives.
• Into One Stream - easy - Some arrive alone, some in batches. Line them all up.
• Letters in the Noise - easy - Case and punctuation are distractions. Find what each letter really weighs.
• Max Length Token - medium - The longest token wins.
• Members Only - easy - Every digit wants in. Only the odd ones make the cut.
• Merge Counters - medium - Two tallies. Combine them.
• Moving Day - hard - Old schema in, new schema out.
• Next in Line - medium - Every server gets its turn. Keep the line honest as the pool changes.
• No Days Off - medium - Show up every day. Miss one and the count starts over.
• No One Left Behind - medium - Every record stays; fill the gaps where a match exists.
• Normalize Name - easy - Names are messy. Standardize them.
• No Shortcuts - easy - The peak value. Built-ins off the table.
• No Vacancy - hard - Every booking needs a room. Find the busiest moment.
• Null Counter - easy - How many holes in the data?
• One Step Behind - medium - What came before this row?
• Open and Shut - easy - Every opener is a promise. The order you close them in decides whether it holds.
• Ordered Character Check - easy - Check if all As appear before all Bs.
• Out of Nowhere - hard - Every stream has a rhythm. Find the readings that break it.
• Parse Log Line - medium - One line. A dozen fields hidden inside.
• Points of Order - medium - Every page makes its case for the top. Settle it, and settle the ties.
• Precision and Recall - medium - Precision and recall. Both matter.
• Prefix Based Word Replacement - medium - Every word trimmed to its root.
• Progress Milestones - easy - Progress at every 10% increment. Keep the receipts.
• Quality Gate - easy - Not everything passes inspection.
• Quantile Calculator - easy - Mark the boundary value at a given point.
• Read Both Ways - easy - Placeholders hide in plain sight. The symmetric ones give themselves away.
• Reads The Same Both Ways - medium - Somewhere in the noise, a stretch that mirrors itself. Find the longest one.
• Record Filter - easy - Some records belong. Others do not.
• Rename Keys - medium - Old names out. New names in.
• Reverse Field - easy - Flip it. See what happens.
• Right of Way - medium - Every packet asks the same question of the firewall. Answer it the way the table intends.
• Roots and Branches - medium - Flat strings carry a hierarchy. Recover it.
• Round and Round They Go - medium - Each face waits its turn as the wheel comes back around.
• Row Aggregates - medium - Each row holds its own summary.
• Sanitize Field - easy - Dirty input. Clean output.
• Schema Checker - easy - The schema says one thing. The data says another.
• Sequential Word Pairs - easy - Everything has a neighbor.
• Shortest Unique Metric Tag - medium - One token per metric. Make it unambiguous.
• Single Element Among Pairs - easy - One element has no partner.
• Single File - easy - However deep the nesting, every voice arrives in its own turn.
• Skip a Beat - easy - Two in a row is never allowed. Collect the most from what remains.
• Sort Descending - easy - Biggest first. No exceptions.
• Steady State - medium - Turn a jittery stream into a calm read, one step at a time.
• Stock Range Finder - medium - Prices move. One stretch had the widest gap.
• Subarray Signal - medium - One stretch carries the strongest signal.
• Sum of Their Parts - medium - A stream of raw actions, folded into one portrait per person.
• The Account Manager - easy - Deposits, withdrawals, and a ledger you can walk back.
• The Additive Chain - easy - Each value is the sum of the two before it - no calls to itself allowed.
• The Address Surgeon - easy - One string hides a street, a city, a state, and a zip.
• The Alphabet Score - easy - Every letter has a secret numeric value - what's your total?
• The Alphabet Sorter - easy - Filing cabinet logic: everything goes in its proper drawer.
• The Balanced Inspector - medium - Every branch should carry the same weight.
• The Balanced Sum - easy - Some numbers have a rare quality that mathematicians revere.
• The Bipartite Test - medium - Can this crowd be split into two perfectly separated groups?
• The Bit Counter - easy - How many lights are on in the binary representation?
• The Bit Reverser - medium - Sometimes the answer is literally backwards.
• The Bitwise Judge - easy - No division, no modulo - just a single bit tells you everything.
• The Blind Multiplier - medium - Compute the result of everything around you - without seeing yourself.
• The Bonus Round - medium - Consecutive matching dice rolls trigger a special scoring rule.
• The Bouncer - easy - Every door has a guest list.
• The Bronze Medalist - easy - Not first, not last - somewhere in the middle of the podium.
• The Bug Spotter - easy - It compiles. The answer is still wrong.
• The Build Order - medium - Some tasks must wait for others to finish first.
• The Calendar Sort - easy - Time has its own opinion about order.
• The Carousel - easy - Keep moving, same ride.
• The Chain Transform - medium - One small step at a time can cover a great distance.
• The Change Tracker - medium - Before and after snapshots. The delta is in there.
• The Character Clans - medium - Words sharing the same letters belong to the same clan.
• The Character Map - easy - Every character leaves a trace. Add them up.
• The Chunked Reader - medium - Too big for one payload. Ship it in pieces.
• The Cipher Wheel - easy - Every letter has an alias - you just need the right codebook.
• The Clock Examiner - medium - Two hands on a clock: how wide is the gap?
• The Code Expander - easy - Compressed messages need a decoder to come alive.
• The Coin Vault - medium - Exact change only - and you want to use as few coins as possible.
• The Column Shuffle - medium - Rows in, columns out. Number them.
• The Column Transformer - easy - Each column gets its function.
• The Complement Hunt - easy - Every number is looking for its other half.
• The Config Blender - easy - Config collision. The surviving values after a merge.
• The Counting Machine - medium - It knows where it stopped last time.
• The Crowd Favorite Eatery - easy - One restaurant clearly won the most hearts.
• The Crowd Pleaser - easy - One value shows up more than all others combined.
• The Crowd Splitter - easy - The middle holds even with a dominant outlier.
• The Custom Iterator - medium - Some sequences follow their own rules.
• The Date Sorter - medium - Jumbled calendar. Sort it first.
• The Decomposer - easy - Every composite thing can be broken down to its simplest parts.
• The Deep Config - medium - Every setting has a path. Trace it down to the value.
• The Deep Dictionary - easy - One key goes further than the rest.
• The Deep Dive - easy - A specific position in the unsorted pile.
• The Deep Selector - easy - Tell it what you want. It knows where to look.
• The Deep Unpacker - easy - Boxes inside boxes. Eventually you reach the bottom.
• The Dependency Resolver - medium - Everything depends on everything.
• The Depth of Field - easy - Some containers hold containers that hold containers.
• The Diagonal Accountant - easy - Two diagonals cross in the center of every square.
• The Dict Comparator - medium - Two dictionaries. Subtle differences.
• The Disputed Fare - medium - One charge, two legs. Finance needs to know which two.
• The Dominant Signal - easy - Hottest items in the transaction log. Ties included.
• The Double-Ended Gateway - medium - Some queues let you skip the line from both ends.
• The Dynamic Container - hard - Grow your own storage before the standard library does it for you.
• The Elevator Trace - medium - Nested floors. One path through.
• The Email Ranker - medium - Some inboxes see more action.
• The Encoded Signal - medium - Letters folded into digits, counts hidden in the punctuation.
• The Even Checkpoint - easy - Is this number in the even club? Prove it the fast way.
• The Event Bucketer - easy - Logs slotted into buckets.
• The Event Window - medium - A five-minute window is all that matters.
• The Eviction Policy - medium - Fixed capacity. The key left idle longest is the one that goes.
• The Exception Handler - medium - Good code handles failure as gracefully as success.
• The Expander - easy - What goes in small comes out big.
• The Face That Breaks the Bank - medium - Roll enough dice and one number always runs away with it.
• The Fallback Layer - easy - When the live values come back empty, something has to stand in.
• The Family Reunion - medium - Two cousins share a common ancestor somewhere above.
• The Fast Climber - medium - Some routes up the mountain are faster than others.
• The Field Counter - easy - Some fields speak louder than others.
• The File Size Profiler - medium - File types and their disk footprint. One type dominates.
• The Fine Print - medium - Risk rules nest deep. Decide which transactions clear them.
• The Firehose - medium - A stream arrives out of order. Roll it up, one time window at a time.
• The First Class Function - medium - Functions travel as values - prove you can pass one around.
• The First Encounter - easy - Every character has a story - but only if you remember where it started.
• The First of Their Kind - easy - When the same record arrives twice, only the first one survives.
• The First Stranger - easy - In a crowd, the unique ones stand out first.
• The Flat Mapper - medium - Nested values. One flat stream out.
• The Forbidden Ceiling - easy - Round up. But not the obvious way.
• The Forbidden Sorter - medium - Put the letters in order without the obvious tool.
• The Forgetful Machine - medium - It remembers everything, until it does not.
• The Forward Fill - easy - Patch the gaps in a noisy sensor stream.
• The Frequency Eviction - hard - When storage is tight, something has to go.
• The Fuller Copy - medium - The same listing lands twice, half-filled each time. Keep what is whole.
• The Gap Filler - easy - Fill the Nones with the last real value.
• The Gaps Between - hard - The data is not as clean as it looks.
• The Gate Keeper - easy - Not all openings have a closing.
• The Generous Ones - medium - The generous ones are obvious.
• The Grid Pivot - easy - A different angle reveals a completely different picture.
• The Half-Life Search - medium - Every guess cuts the problem in half.
• The Halftime Score - easy - Middle value of a dataset. No built-in shortcuts.
• The Hash Stamper - easy - One input, one irreversible output - the foundation of every secret.
• The High Mark - easy - Scan the list. Report the max.
• The High Rollers - medium - Not every gambler bets the same - some wager far more than others.
• The Horizon Scanner - medium - For each position, what is coming up ahead?
• The Hostile Takeover - medium - One dict eats another.
• The Hourly Bucket - medium - Timestamps belong somewhere.
• The Indivisibles - easy - Numbers that yield only to themselves.
• The Infection Spread - hard - It starts with one, and then it spreads.
• The Integer Sieve - easy - Not everything in this list belongs here.
• The Intervals - medium - Timestamps in buckets.
• The IP Validator - easy - Real and fake, mixed together.
• The Island Counter - medium - Surrounded by water, connected by land - how many separate landmasses?
• The Last Instance - easy - When duplicates appear, only the last one counts.
• The Last Known Good - medium - When a column goes quiet, its last reading keeps standing.
• The Last Seen Map - easy - For each character, where did it appear last?
• The Lazy Squares - easy - A sequence that never fully reveals itself.
• The Lazy Stream - hard - Some slots hold one value, some hold a batch. Level them out.
• The Lazy Unpacker - medium - Peel back every layer until only the values remain.
• The Letter Census - easy - Every crowd has its share of talkers and quiet ones.
• The Letter Frequency Map - easy - Count every character in the string and report the results.
• The Letter Kin - medium - Words that share the same letters belong together.
• The Letter Ledger - easy - Every character has a count to answer for.
• The Letter Mapper - medium - A consistent substitution, or not.
• The Letter Tally - easy - Each character in the string has a count to answer for.
• The Level Inspector - medium - Each floor of the tower tells a different story.
• The Level Summer - medium - Every tier of the hierarchy keeps its own total.
• The Line Cutter - easy - Did everyone with an A-pass get through before the B-crowd arrived?
• The Line Splitter - easy - Comma-separated truths, one at a time.
• The Link Shrinker - medium - Long addresses have aliases - you give them out, you keep the map.
• The Listeners - medium - Subscribers show up, listen, and sometimes leave.
• The List Merger - easy - No shortcuts.
• The Log Decoder - easy - Every line holds a secret.
• The Log Pulse - easy - Some lines repeat themselves.
• The Lone Character - easy - It appeared exactly one time. That made it special.
• The Lone Traveler - easy - One character stands apart from the crowd.
• The Long Run - easy - Say it once, then say how many times it kept saying it.
• The Long Way Around - easy - Anyone can call the function. Order it by hand.
• The Loudest Voice - medium - One event type is drowning out the rest. Find it.
• The Low That Came Too Late - easy - You only get to buy before you sell. Find the biggest gain the day allowed.
• The Map Reducer - medium - Map it. Reduce it. One answer.
• The Market Streak - medium - Some stocks run longer than you think.
• The Market Timer - medium - Buy low, sell later. The whole game is when.
• The Matching Manifest - easy - Two warehouses, one shipment - only load what's in both.
• The Merge - easy - Chaos in. Order out.
• The Merge Champion - medium - Many sorted rivers flowing into one.
• The Messy Pipeline - easy - The upstream API has no idea what a schema is.
• The Middle Ground - hard - The middle value keeps moving.
• The Min Tracker - medium - The stack remembers the best it ever saw.
• The Minutes Tracker - easy - Some activities eat more time than others.
• The Mirror Flip - easy - Sometimes the fastest fix is to swap everything.
• The Mirror Image - easy - Flip the tape backwards - start from the end.
• The Mirror Index - easy - Every value remembers who pointed to it.
• The Mirror Test - easy - Check if a string reads the same forwards and backwards.
• The Mirror Words - easy - Each word looks back at itself.
• The Missing Number - easy - Something is missing from the sequence.
• The Molecule Report - easy - Four letters. A lot of math hidden in the sequence.
• The Month-by-Month Snapshot - medium - Every salesperson has a story. The months just tell it sideways.
• The Multiplication Trail - easy - Each step multiplies the whole journey.
• The Multiplier Rush - medium - Negatives cancel negatives - but only if you keep both in view.
• The Narrow Lens - medium - A narrow timeframe. Everything inside matters.
• The Nearest Value Mapper - medium - Close enough counts. Ties go low.
• The Never-Ending Sequence - easy - Sequence that keeps going. Follow it.
• The Numbered Chair - easy - A standing list. Position n holds one entry.
• The Number Miner - medium - JSON strings are hiding numeric secrets. Dig them out.
• The Number Narrator - medium - Every number has a story in words.
• The Number Screen - easy - Some numbers make the cut. Most do not.
• The Odd Digits - easy - Hidden inside a mess of characters are a few odd numbers.
• The Odd Extractor - easy - Not all numbers from a string are welcome here.
• The Ones That Come Back - easy - In a column that promised uniqueness, some values kept their seat. Name them.
• The Ones That Count - easy - Not every minute counts. Add up the ones that do.
• The One-Timers - easy - Values that never repeated.
• The One-Way Street - easy - The longest stretch that never turns around.
• The Onion Layer - hard - Peel from the outside in - one ring at a time.
• The Online Elite - medium - The top performers are hiding in the data.
• The Only Difference - easy - Two versions of the same line. Surface only what changed.
• The OOP Pillars Exam - medium - Four principles, one class hierarchy - show you know all of them.
• The Op Dispatcher - easy - Name the operation, apply it everywhere.
• The Order Enforcer - easy - Some rules say every A must come before every B.
• The Order Inspector - medium - A binary tree has rules - is this one actually following them?
• The Original Keeper - easy - Clean up duplicate events without losing the timeline.
• The Output Peak - hard - One stretch outpaced all the others.
• The Overlap - hard - Overlapping windows are one outage. Collapse them into the truth.
• The Overlap Finder - easy - Two guest lists - who made it onto both?
• The Overwritten Hour - medium - The log wrapped on itself. The order is still there, just not where you would look.
• The Page Turner - medium - Nobody loads everything at once.
• The Pair Counter - easy - How many pairs can be formed from the crowd?
• The Paired Doors - easy - Every door you open is a promise to close it, in order.
• The Parentheses Factory - medium - Building balanced brackets is an art form.
• The Pascal Row - easy - Each number is the sum of two numbers above it.
• The Password Builder - easy - Random characters, fixed rules.
• The Password Forge - easy - Does this password pass the strength gate?
• The Path Inward - medium - Every setting hides a few levels down. Follow the route, or come back empty.
• The Pay Ladder - medium - Climb the ladder the hard way. No shortcuts allowed.
• The Peak Finder - easy - Largest number in the list. Max() is not an option.
• The Perfect Match - medium - Two numbers walk into an interview...
• The Placement Fixer - medium - Each value belongs in exactly one spot.
• The Portfolio - medium - Count every bed under a name. The largest holdings rise first.
• The Postfix Processor - medium - Math without parentheses - the operators come after the numbers.
• The Precision Hunt - medium - Some answers need no decimal point.
• The Price Bander - easy - Different prices, different treatment.
• The Priority Queue - medium - When two things tie, something has to break the deadlock.
• The Progress Meter - medium - Ten glimpses of a run, no matter how long it ran.
• The Progress Parade - easy - Just tell them how far along you are.
• The Quarter Turn - medium - One rotation changes everything.
• The Queue Disguise - medium - A queue in sheep's clothing.
• The Quiet Drift - medium - Two versions of the same truth.
• The Quiet Hours - medium - Overlapping outages hide how much time is really dark. Collapse them into the truth.
• The Ranked Dict - easy - Values deserve order too.
• The Repeat Offenders - easy - Repetition is a clue.
• The Repeat Review - medium - The echo came back.
• The Repeat Visitor - medium - Loyal customers come back sooner than expected.
• The Response Aggregator - medium - Multiple result pages. One clean summary.
• The Resume Sifter - medium - Pull what's useful. Skip what you know.
• The Roll Call - easy - Every value is waiting for its name.
• The Rolling Peak - medium - The sweetest stretch in the sequence.
• The Roman Converter - easy - Roman numerals decoded.
• The Rotated Array - medium - Someone shuffled it. Now locate what you came for.
• The Runner-Up - easy - Not the winner. The one just behind it.
• The Running Total - easy - Each position holds the sum of everything before it.
• The Safe Caster - easy - Type conversion is easy, until it is not.
• The Schedule Cleaner - medium - Overlapping sessions. One clean line.
• The Schema Diff - medium - Two versions of the same config - what changed between them?
• The Scoreboard Race - medium - The first to cross the line ends the game, mid-round or not.
• The Score Sorter - easy - Points on the board, sorted by who earned the most.
• The Scramble Check - easy - Same letters, different order - are these two strings secret twins?
• The Second Summit - easy - Not the top of the mountain - just below it.
• The Secret Twins - easy - Same letters, different disguises.
• The Self-Portrait Number - easy - Some numbers describe themselves perfectly.
• The Sequel Spotter - easy - Spot the sequels hiding in the catalog.
• The Shadow Cleaner - easy - Remove the repeats. No shortcuts.
• The Shape They All Share - medium - A pile of exports, no two quite alike. Keep only what every record agrees on.
• The Shifting Standard - medium - A benchmark in motion.
• The Short Address - medium - Every link needs a slug small enough to type by hand.
• The Shortest Path Home - medium - Every leaf remembers the road it came from. Bring them all back on one line.
• The Shortest Route - medium - Fewer hops is always better.
• The Shortlist - medium - In every field, only a few rise to the top. Keep them.
• The Silent Locator - easy - Every lookup should cost you less than the one before it.
• The Silver Screen Summit - medium - Box office totals decide who makes the top of the marquee.
• The Single Bit - easy - One particular pattern hides in plain sight.
• The Slow Leak - medium - Nested groups. One flat stream.
• The Sneaky Twins - medium - They look different but they are the same inside.
• The Social Graph - easy - Everyone knows someone.
• The Solo Act - easy - One-and-done values only.
• The Spaces Between - medium - Every voided trip leaves a hole in the sequence. Find the one that matters.
• The Spin Doctor - medium - Ninety degrees, but which way?
• The Spiral Harvest - medium - The snail reads the grid in its own special order.
• The Spread - easy - Data spread around a center. The range matters.
• The Squeeze - easy - aaabbb gets old fast. Shrink it.
• The Staircase Problem - medium - One step or two, the choices add up.
• The Status Board - medium - A pile of raw access logs, and two numbers that matter hiding inside the quotes.
• The Step Counter - easy - You can hop one step or two - how many ways to reach the top?
• The Streak Breaker - easy - It has a problem with repetition.
• The Stream Averager - easy - The answer moves with the data.
• The Stream Joiner - hard - Events don't wait for each other. This does.
• The String Shrinker - easy - Compress the string. Shorter wins.
• The Style Guide - easy - Not every word deserves the same treatment.
• The Sum of Its Parts - medium - Every assembly hides smaller ones. Count what it really takes to build.
• The Syntax Sentinel - easy - Brackets opened and closed. The nesting might be off.
• The Table Thief - medium - Somewhere in that query, tables are hiding.
• The Tag Analyst - medium - Two sets of labels, one analysis.
• The Tail End - easy - Push, pop, peek. The basics that break people.
• The Tail Finder - medium - Navigate to the end of a linked list using recursion.
• The Tail Trimmer - easy - Remove the k-th item from the back without counting forward first.
• The Tallest Stacks - medium - Every terminal has its records. Find the two that stand tallest.
• The Tally Counter - easy - How many times does a single guest show up to the party?
• The Target Hunt - medium - Pairs that hit a target. Every one of them.
• The Throttle Ceiling - medium - Too many requests in too short a timeframe. Throttle it.
• The Throttle Wall - hard - Stop the abusers. Let the rest through.
• The Timezone Trap - medium - Trip data and timezones. They're not the same thing.
• The Timing Decorator - medium - Wrap any function to capture how long it takes.
• The Title Ladder - medium - Job titles and the salary tier they belong to.
• The Top Reviewer - easy - One restaurant receives the most feedback - which one?
• The Top Words - medium - In every document, some words dominate the conversation.
• The Trade Signal - easy - Buy low, sell high. Identify the ideal moment.
• The Traffic Director - easy - Spread the load evenly - nobody should be doing all the work.
• The Trapped Pool - hard - What collects in the valleys after the rain?
• The Tree Measurer - easy - How deep does the rabbit hole go?
• The Trip Aggregator - medium - Travel records hold patterns waiting to be surfaced.
• The Trip Grouper - easy - Where did everyone go, and for how long?
• The Triple Alliance - hard - Three numbers, one target.
• The Triplet Hunt - medium - Every path that works gets a seat at the table.
• The Type Sorter - easy - A mixed list is hiding its numbers - extract them.
• The Unbroken Line - medium - The longest stretch that never repeats itself.
• The Value Sorter - easy - The order was always negotiable.
• The Velvet Rope - medium - Some users get in. Others wait outside until the window resets.
• The Version Parade - easy - 1.0 before 2.0. Don't let the dots confuse you.
• The Version Ranker - medium - Software versions follow their own ordering rules.
• The Vocabulary Test - medium - Every character has to come from a word you already know.
• The Vowel Hunt - easy - Just the vowels. All of them.
• The Waiting Game - medium - Patience has a price - and a count.
• The Water Collector - hard - Two walls, one sky, and a very important question.
• The Water Gauge - medium - Elevation bars trap water in the dips. Total the volume.
• The Weight of the Book - medium - Every holding pulls its weight. Order the asset classes by what they carry, and let the ties settle by name.
• The Wide View - hard - Long format is easy. Wide format is useful.
• The Window Cleaner - medium - Keep it fresh, keep it unique.
• The Word Census - easy - Who said what - and how many times?
• The Word Counter - easy - How many times does each word show up in a file?
• The Word Families - medium - Different spellings, same letters - they belong together.
• The Word Flipper - easy - The sentence stays, the words surrender.
• The Word Inventory - easy - Every word, twice over.
• The Word Map - easy - Language, quantified.
• The Yahtzee Engine - hard - Five dice. Six faces. Score it.
• The Yahtzee Scorer - medium - Dice scoring. Multiple categories evaluated.
• The Zero Propagator - medium - One zero can change the whole picture.
• The Zigzag Encoder - medium - The message snakes its way across the rails.
• Three That Hold - medium - Not every triangle is a triangle.
• Threshold Filter - medium - Above the line or below it.
• Top-Heavy - medium - The widest row leads, and everything below it narrows.
• Top N Keys - medium - Most of them do not matter. The few that do stand out.
• Transform Column - easy - Same data, new shape.
• Twice on the Wire - easy - A dropped ACK makes the reader say it again. Keep the signal, drop the echo.
• Unbroken - easy - A single dip resets the clock. Find the longest the machine held steady.
• Unique Values - easy - Duplicates are noise. Remove them.
• Validate Email - medium - Looks like an email. But is it?
• Value Count - easy - How many of each? Count them.
• Ways of Reading - medium - One key, no separators, and more than one story it could tell.
• What Changed Overnight - medium - Schema from yesterday vs today. Something changed.
• What's Left Standing - medium - They only meet head-on, and only mass decides who keeps going.
• What Stays Warm - medium - Memory is small and the stream never stops. Keep only what was just asked for, in the order it was asked.
• What the Card Remembers - medium - A hold on your money is never a single moment. Rebuild the windows it actually lived in.
• What the Day Left Open - medium - Every fill moves a position. Reconstruct where the book settled by the close.
• What the Night Changed - hard - Two photographs of the same table, a day apart. Account for everything that moved.
• What Won't Convert - easy - Some values become numbers. The rest become nothing.
• When Hours Collide - medium - Two reservations, one slot. Find every clash.
• When the Hours Touch - medium - Two sessions that overlap are really one. Find the windows a driver was actually online.
• Where the Buck Stops - hard - A pile of reporting lines, no order to them. Somewhere in the bag sits the one with no boss.
• Where the Deltas Settle - medium - Every stretch of the stream tells its own story. Count the ones that settle to your number.
• Where the Line Breaks - easy - Every batch has a last piece. Mark it right.
• Where the Lines Break - easy - Every record hides its fields behind noise. Pull the real ones loose.
• Where They Part - hard - They all start the same way. How far?
• Who Came First - easy - The feed repeats itself. Keep each member only the first time it speaks.
• Who Gets In - medium - When the roster changes, does access follow?
• Word Counter - easy - Words in, counts out.
• Zip to Record - easy - Two lists become one record.