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Counting Chocolate Description: Cady’s Chocolate Company just opened down the street! Cady’s chocolate is world famous, and her recipe is top secret. But the company is more renowned for the fact that they sell the chocolate in random quantities. Each box of chocolate may contain anywhere from $1$ ...
27,000
Counting Clauses Description: It’s time for the annual 3-SAT competition, where the contestants compete to answer as many instances of 3-SAT as possible within the time limit. 3-SAT is a classic NP-complete problem, where you are given a boolean formula in conjunctive normal form, in which we have a se...
27,001
Counting Codes Description: You’re one of the king’s spies sent on a secret mission to retrieve an item of incredible value, an ancient scroll from the throne room. Legend has it, the scroll contains the answer to the $P$ versus $NP$ problem. When you finally reach the throne room, you realize ther...
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Counting Days Description: When doing competitive programming, one can sometimes fall into an almost trance-like state. Minutes becomes hours, hours becomes days, and suddenly you don’t even know for how many days you have been programming! Of course, this just became another problem for you to solve b...
27,003
Counting Greedily Increasing Supersequences Description: Given a permutation $A = (a_1, a_2, \dots , a_ N)$ of the integers $1, 2, \dots , N$, we define the greedily increasing subsequence (GIS) in the following way. Let $g_1 = a_1$. For every $i > 1$, let $g_ i$ be the leftmost integer in $A$...
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Counting Palindromes Description: A palindrome number is a non-negative number without leading zeroes, that reads the same forward or backward. For example, $12321$, $44$ and $9$ are palindrome numbers, while $010$, $123$ and $100$ are not. Given a positive integer $n$, a prime number $p$ and a non-negati...
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Counting Satellites Description: Nick likes satellites. He likes them so much that he looks for them everywhere. One day he found a string of letters and counted a lot of instances of the word “SATELLITE” among all subsequences of the string. However the next day he forgot this string. Can you help him ...
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Counting Staircases Description: Umi Matsuzaki is raising signal flags to wish sailors good luck. She has $N$ flags with different heights. Her $N$ flags are represented by distinct integers $a_1, a_2, a_3, \dotsc , a_N$, where $a_i$ corresponds to the height of the $i$th flag. Umi realizes that h...
27,007
Counting Stars Description: The field of astronomy has been significantly advanced through the use of computer technology. Algorithms can automatically survey digital images of the night sky, looking for new patterns. For this problem, you should write such an analysis program which counts the number ...
27,008
Counting Subsequences (Hard) Description: “$47$ is the quintessential random number," states the $47$ society. And there might be a grain of truth in that. For example, the first ten digits of the Euler’s constant are: ``` 2 7 1 8 2 8 1 8 2 8 ``` And what’s their sum? Of course, it is $47$. Try walking...
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Counting Trees Description: The Great Lord Pooty likes trees and orders his subordinates to have them colored black and white. The trees have $n$ vertices labeled from $0$ to $n-1$, are rooted at vertex $0$, and have a peculiar structure elaborated on below. A tree has a fixed branching factor $k ...
27,010
Counting Triangles Description: The following figure contains a lot of triangles, $88$ in fact. Two of them are highlighted. The figure is made up of 15 line segments. You have a triangle if you can start at an intersection of line segments $a$ and $b$, follow $b$ until it intersects with some line...
27,011
Couple Competition Description: Hori-san and Miyamura-kun have bought a new game to play with to show their precious and eternal love for one another. Being competitive and loving at the same time, they both want to win the game. This game can be modelled in a form of $N$ rectangular blocks with a heights...
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Coupons Description: Johan lives in Stockholm, which means he has to travel a lot by bus and subway. To travel, he needs to pay a number of coupons, depending on which zones his trip goes between. A ticket is specified by an interval $[A, B]$ of zones it is valid in, and costs $2 + |A - B|$ coupon...
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Course Planning Description: Tom is an upcoming senior undergraduate student planning for his courses for the final year. The final year will have two semesters, in which there are $n$ courses offered numbered from $1$ to $n$. Course $i$ has a difficulty level $d_ i$. Two courses may be on a same t...
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Course Scheduling Description: It is a difficult job to schedule all of the courses in a university to satisfy students’ choices with a minimum of conflicts. The task is made all the more difficult when some students don’t pre-enroll, or pre-enroll multiple times because they forget that they already d...
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Cousins Description: Two strings $a$ and $b$ are defined to be first cousins if they can be made equal by removing no more than half the characters from each. For example, “abcdef” and “axcyd” are first cousins because we can remove $3$ of the $6$ characters (b, e, and f) from the first string ...
27,016
Covel Playlist Description: The music playlist at Covel (now dubbed Epicuria) offers instrumental tracks that students just can’t get enough of. The songs consist of $N$ piano notes (A-G) and they are always so catchy. As a result, students decide to use the app Shazam to figure out what songs to a...
27,017
Cover up Description: Dezider is making a game board for the game of Convexity. He drilled a bunch of holes in a piece of wood. As the name of the game suggests the holes were on the boundary of a convex polygon. After turning over the piece of wood, Dezider froze—he had damaged the famous Picasso lith...
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Coverage Description: A cellular provider has installed $n$ towers to support their network. Each tower provides coverage in a $1\text { km}$ radius, and no two towers are closer than $1\text { km}$ to each other. The coverage region of this network is therefore the set of all points that are no more t...
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Covered Walkway Description: Your university wants to build a new walkway, and they want at least part of it to be covered. There are certain points which must be covered. It doesn’t matter if other points along the walkway are covered or not. The building contractor has an interesting pricing scheme. ...
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Cow Crane Description: Farmer Laura has a barn. In her barn, she has two cows, Monica and Lydia. Monica and Lydia love food, and they are quite lazy. For most of the day they chill out in the barn, waiting for Laura to come serve them a nice meal. Farmer Laura is always very precise about when to serve...
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Cowboy Checkers Description: Theta likes to play a board game called Cowboy Checkers, also known under the name “Nine Men’s Morris.” This strategy board game, which dates at least to the Roman Empire, is played by two players on a grid with $24$ intersections, or points, as shown on the left in Figure ...
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Crabbles Description: Jennifer is practicing for a Crabbles tournament. She pulls out a handful of Crabbles tiles out of a bag, and tries to form the word with the highest possible score. Each tile contains a letter (used to form the word) and a number (its score value). She can use each tile at most o...
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Cracker Barrel Game Description: In this problem, you are giving a start position of between $1$ and $14$ pegs of different colors, as well as a target color. You should output whether it is possible to remove all but one peg from the board using the usual rules and end up with a peg that is of the tar...
27,024
Cracking RSA Description: RSA is a widely used public-key cryptosystem that allows two parties (such as people or computers) to exchange secret messages without revealing information to anyone else listening on the conversation. Many websites use RSA when visited over a secure https connection. In RSA,...
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Cracking The Safe Description: This particular safe has $9$ buttons with digital displays. Each button shows a single digit in the range $0..3$. When you push one of the buttons, the number it displays is incremented by $1$, circling around from $3$ to $0$. However, pushing a button will also increment the...
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Cracking the Code Description: A terrorist organisation known as the New World Ensemble for Rebellious Coders (NWERC) is a menace to our society. Fortunately, we have found a way to intercept their communications without them knowing it. There is a problem however, since their messages are encrypted. ...
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Cram Description: You want to compress a given text passage using backreferences. A backreference is a pair of numbers $[a,b]$ indicating that the next $b$ characters of the string are the same as the $b$ characters starting $a$ characters back from the current position. The two strings may overlap...
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Cramming for Finals Description: It’s final exam season and Ashley is heading to her favorite library to cram for finals. The library has a dedicated floor for studying where there are $r$ rows of $c$ tables evenly spaced. Each table only has room for one student, and some students have already ar...
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Crane Description: There are $n$ crates waiting to be loaded onto a ship. The crates are numbered $1, 2, \ldots , n$, the numbers determining the order of loading. Unfortunately, someone messed up the transit and the crates are standing in a row in an arbitrary order. As there is only limited space...
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Crane Balancing Description: Wherever there is large-scale construction, you will find cranes that do the lifting. One hardly ever thinks about what marvelous examples of engineering cranes are: a structure of (relatively) little weight that can lift much heavier loads. But even the best-built cranes m...
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Cranes Description: A crane is a wonderful tool for putting up a building. It makes the job go very quickly. When the building must go up even faster, more than one crane can be used. However, when there are too many cranes working on the same building, it can get dangerous. As the cranes spins around,...
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Crashing Robots Description: In a modernized warehouse, robots are used to fetch the goods. Careful planning is needed to ensure that the robots reach their destinations without crashing into each other. Of course, all warehouses are rectangular, and all robots occupy a circular floor space with a diam...
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Craters Description: General Warren Pierce has a bit of a problem. He’s in charge of a new type of drone-delivered explosive and they’ve been testing it out in the Nevada desert, far enough from any population center to avoid civilian casualties and prying eyes. Unfortunately word has gotten out about ...
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Crazed Boar Description: A crazed boar has become lost in the forest! In its madness, it will charge in a random direction at blazing speed, until it has traveled a distance $d$, or until it hits a tree (in which case the boar will become dazed and end its charge), whichever comes first. Given the layo...
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Crazy Driver Description: In the Linear City, there are $N$ gates arranged in a straight line. The gates are labelled from $1$ to $N$. Between adjacent gates, there is a bidirectional road. Each road takes one hour to travel and has a toll fee. Since the roads are narrow, you can only travel from gates...
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Creative Accounting Description: When accounting for the profit of a business, we can divide consecutive days into fixed-sized segments and calculate each segment’s profit as the sum of all its daily profits. For example, we could choose seven-day segments to do our accounting in terms of weekly profit...
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Credit Card Payment Description: Using credit cards for your purchases is convenient, but they have high interest rates if you do not pay your balance in full each month. The interest rate is commonly quoted in terms of “annual percentage rate” (APR) which is then applied to the outstanding balance ea...
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Cribbage On Steroids Description: Cribbage is a two-person card game where players score points for various combinations of cards. A standard $52$-card deck is used where cards have one of $4$ suits (not important in this problem) and one of $13$ ranks. The card ranks, from lowest to highest, are A...
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Cricket Deadpool Description: Kyle is working on a graduate degree in biology, and as part of his research he is studying the eating habits of a certain snake species. One of these snakes, named Donna, lives in a terrarium in Kyle’s lab, where she is fed a steady diet of crickets. To pass the time (and...
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Criss-Cross Description: Peter is bored during his operating systems class, so he draws doodles on a sheet of paper. He feels like drawing abstract art using his ruler: he draws line segments by choosing two points in the plane and connecting them. Lots of them. Can you write a program that counts the...
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Criss-Cross Cables Description: As a participant in the BAPC (Bizarrely Awful Parties Competition) you are preparing for your next show. Now, you do not know anything about music, so you rip off someone else’s playlist and decide not to worry about that any more. What you do worry about, though, is the...
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Critical Elements Description: Zapray really loves the Algorithmic Problem Solving course, but he is struggling with it. Recently the class studied Longest Increasing Subsequence (LIS). Zapray knows well how to compute the length of LIS for a given sequence. But on the exam paper there appears to be a ...
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Crne Description: Thrilled about his new valid set of pieces, Mirko rushed over to Slavko’s, to find that Slavko too found a set of chess pieces in his attic. Slavko’s set, miraculously, contains only black pieces. But since neither of them can play chess, they settled on smashing one another senseless...
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Crni Description: Even though he has found all the most amusing rides at the amusement park, Mirko’s enthusiasm still isn’t fading. He opened his graph paper notebook and started colouring squares, and a new, even harder problem dawned on him. You are given a square table consisting of N rows by N col...
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Crop Triangles (Easy) Description: Note that this is an easier version of the problem crophard. Some pranksters have watched too much Discovery Channel and now they want to build a crop triangle during the night. They want to build it inside a large crop that looks like an evenly spaced grid from abov...
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Crop Triangles (Hard) Description: Note that this is a harder version of the problem cropeasy. Some pranksters have watched too much Discovery Channel and now they want to build a crop triangle during the night. They want to build it inside a large crop that looks like an evenly spaced grid from above...
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Cross Description: In the game of Sudoku, the objective is to place integers between $1$ and $9$ (inclusive) into a $9\times 9$ grid so that each row, each column, and each of the nine $3\times 3$ boxes contains all nine numbers. The starting board is partially filled in so that it is possible ...
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Cross Country Description: Charles Johnson is on his way to meet his very good friend Bernard Terrell. They are going on their bi-weekly skiing trip. Today Charles had forgot all about the Kvikk Lunsj and had to go back home to get it. This has left him very late, and to make things worse all the parki...
27,049
Crowd Control Description: The BAPC draws a large number of visitors to Amsterdam. Many of these people arrive at the train station, then walk from intersection to intersection through the streets of Amsterdam in a big parade until they reach the BAPC location. A street can only allow a certain number of ...
27,050
Crusaders of the Lost Mark Description: Apple Bloom, Sweetie Belle and Scootaloo are trying to discover their calling, and so they are trying various things to see what they are good at. Today, they decided to help ponies find suitable housing. They need to process the applications of ponies who want t...
27,051
Crypto Trouble Description: Mr. Krabs is a hardcore cryptocurrency and blockchain technology enthusiast. In a recent conference, he heard about a new cryptocurrency called ByteConn333ct, which promises a very high rate of return. He wants to invest in this cryptocurrency, but its unique conversion rate...
27,052
Cryptographer's Conundrum Description: The walls of the corridors at the Theoretical Computer Science group (TCS) at KTH are all but covered with whiteboards. Some of the faculty members are cryptographers, and like to write cryptographic puzzles on the whiteboards. A new puzzle is added whenever someo...
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Cryptographic Keys Description: Lukáš invented a special cryptographic algorithm. He can not tell you the details, of course. However, there is one problem. He doesn’t know how to select strong keys for messages. Can you help him? Suppose that a message is a positive integer $N$. The strongest key is an i...
27,054
Crystal Crosswind Description: You are part of a scientific team developing a new technique to image crystal structures at the molecular level. The technique involves blowing a very fine wind over the surface of the crystal at various angles to detect boundaries (indicated by molecules that are exposed...
27,055
Cu Chi Tunnels Description: The tunnels of Cu Chi are an immense network of underground tunnels connecting rooms located in the Cu Chi District of Ho Chi Minh City. The Cu Chi tunnels were the location of several military campaigns in the 1960s. Nowadays, it is a popular tourist destination. There are...
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Cubic Cycle Description: Consider an undirected graph $G$ with vertices $V$ and edges $E$. A Hamiltonian Cycle is a subset of edges $C \subseteq E$ such that every vertex in $v$ is the endpoint of precisely two edges in $C$ and the graph $H$ with vertices $V$ and edges $C$ is connected. In simpler ...
27,057
Cuboid Slicing Game Description: Ruben and Albert are what you can call abnormally smart. They are also both very fond of mathematically inspired games. Their only problem is that most games are too easy for them, and they end up beating everyone who dares challenge them. Because of that, they’re now m...
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Cuckoo Hashing Description: A stronger variant is Cuckoo Hashing1. The idea is to use two hash functions $h_1$ and $h_2$. Thus each string maps to two positions in the table. A query string $q$ is now handled as follows: you compute both $h_1(q)$ and $h_2(q)$, and if $T[h_1(q)]=q$, or $T[h_2(q)]=q$...
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Cuckoo! Cuckoo! Description: If the count is reached on the hour, report the time at the start of that hour. That is, you may assume the cuckoo finishes sounding off before the minute is up. ## Input The input consists of 2 lines. The first line contains the current time in the form HH:MM where $1 \leq \...
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Cucumber Conundrum Description: Both Maj’s sandwich and the pickles have a circular shape. The sandwich has radius $s$ cm and the pickles have radius $r$ cm. Maj has exactly $n$ pickles. She wants to place as many of them as possible on her sandwich, as long as: * at most $z \% $ of the area ...
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Cudak Description: Božo is a strange little boy. Every day he tires his friends with strange questions. Today’s question is: how many integers in the interval $[A, B]$ are there such that the sum of their digits is $S$, and which is the smallest such number? Write a program that answers Božo’s questio...
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Cudoviste Description: Mirko got his driver’s license! To celebrate that joyous occasion, his parents bought him his first car: a monster truck! Mirko found out that even though having a car that can squash all other cars is nice in traffic jams, parking a car that is the size of $4$ normal cars ca...
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Cumulative Sums Description: While learning mathematics at school, Hieu amazingly invented a new sequence of numbers. It can be defined as below: Here $sod(X)$ is the sum of digits of $X$ (in base $10$) The first few elements of sequence $A$ is $[1,2,4,8,16,23,28,38,49,62,70,77,91,\ldots ]$. Hieu...
27,064
Curious Cupid Description: There are $K$ different languages in the world. Each person speaks one and only one language. There are exactly $N$ single men and $N$ single women. Cupid, the god of love, wants to match every single man to a single woman, and vice versa. Everybody wants to find a partner w...
27,065
Curse the Darkness Description: You are trying to read in a dark room. The room contains many candles, but none are lit. You are considering that it might be worthwhile to light one, but before you do you want to be certain that it will actually light your book. You only get to light one and each is br...
27,066
Cursed Cactus Challenge Description: You are given a simple connected graph $G$ with $n$ vertices and $m$ edges. Each vertex $i$ has a value $a_ i$. No two edges connect the same pair of vertices. Interestingly, each edge lies in at most one simple cycle. A simple cycle is a sequence of $k$ distinct vertices ...
27,067
Curve Speed Description: To help with vehicle stability, the outer edge of a road in a curve is raised with respect to the inner edge. This is called superelevation and is specified as the difference in elevation divided by the width of the road. It needs to be higher for faster speeds and sharper curv...
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Curveknights Description: The hit new RPG mobile game Curveknights was recently released and Yraglac has been absolutely obsessed with it. Yraglac has been trying to farm materials for hours on end so he can promote his units but has suddenly realized that he has forgotten about an integral system that...
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Curvy Little Bottles Description: In her bike rides around Warsaw, Jill happened upon a shop that sold interesting glass bottles. She thought it might make an interesting project to use such bottles for measuring liquids, but this would require placing markings on the bottles to indicate various volume...
27,070
Customs Controls Description: With lifted restrictions, the border trade between Norway and Sweden will surely be back to its former glory. But the authorities are worried that this will also mean an increase of illegal smuggling of goods. The customs authorities of Norway and Sweden must cooperate to ...
27,071
Cut It Out! Description: You are given two convex polygons $A$ and $B$. It is guaranteed that $B$ is strictly contained inside of $A$. You would like to make a sequence of cuts to cut out $B$ from $A$. To do this, you draw a straight line completely through $A$ that is incident to one of the edges...
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Cut in Line Description: You are currently standing in line, waiting to buy some algorithm books at the university book shop. Of course, the line is incredibly long. Even worse, some of your fellow university students keep cutting in line! In fact, this has been going on for such a long time you are un...
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Cut the Negativity Description: An airline tracks costs of flights between $n$ different cities in a table. The cities are numbered from $1$ to $n$. In the table, the entry in $\textrm{row}~ i$ and $\textrm{column}~ j$ represents the cost of a direct flight from $\textrm{city}~ i$ to $\textrm{city}~ j$...
27,074
Cutting Brownies Description: John Horton Conway (1937-) is a British mathematician with many contributions to mathematics. He is famous for the invention of the cellular automaton, more popularly known as the “Game of Life.” This problem is inspired by a game Conway invented in the 1970s. This game i...
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Cutting Cheese Description: Swiss cheese such as Emmentaler has holes in it, and the holes may have different sizes. A slice with holes contains less cheese and has a lower weight than a slice without holes. So here is the challenge: cut a cheese with holes in it into slices of equal weight. By smart ...
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Cutting Corners Description: You work for a day care center. You have a big tub of convex polygons that you are going to let the children play with. However, you notice that some of the shapes have pointy corners. You decide to make them safer by cutting off the most pointy corners as illustrated below...
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Cutting Edge Description: In recent years, the automated manufacturing of various kinds of 3D objects has been a growing trend among hobbyists worldwide. Your friend Lewis has fully bought into this trend, in the sense that his garage is now lined with various kinds of 3D printers and other expensive m...
27,078
Cutting Proteins Description: Your friend Björn has recently started a large chemistry experiment with the goal of creating a secret protein. All proteins are described with strings of letters from a-z, for example, bcaa and hello. He needs to create several so-called pure proteins. These are proteins ...
27,079
Cutting Strings Description: You are given a string $s$ and an integer $k$. You can remove at most $k$ non-intersecting substrings from $s$. Your task is to find the alphabetically (i.e., dictionary order) largest resulting string. For example, with string abcdcada and $k{=}2$, you can choose ...
27,080
Cutting a Rectangle Description: Irus had a rectangle. Irus cut the rectangle and obtained two rectangles. He then put one aside and cut the other one, and continued cutting the same way (never cutting rectangles that were put aside) until he had $K$ rectangles. The edges of all the rectangles have int...
27,081
Cutting a polygon Description: Given is a simple but not necessarily convex polygon. Given is also a line in the plane. If the polygon is cut along the line then we may get several smaller polygons. Your task is to find the length of the cut, that is the total length of the segments in the intersection...
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Cutting the Necklace Description: A group of friends was given a necklace. The necklace is a circular nylon wire with gold beads of various weights glued on. They want to cut the wire into segments so that everybody gets one segment, every person gets the same amount of gold, no bead is cut, and no gol...
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Cvjitici Description: On a faraway planet, strange plants with two stems can be found. Every plant on the planet can be described by three numbers: the $x$-coordinates $L$ and $R$ of the two stems, and the height $H$ at which the stems are connected. The following image depicts a plant with $L=2$, ...
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Cyanide Rivers Description: Cyanide rivers flowing out from Martian south polar ice cap are quite dangerous due to their toxic contents and any activity in their close proximity is often extremely time consuming. A row of communication towers has been built in the area, before the rivers even appeared...
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Cycles (Easy) Description: Note that this is an easier version of the problem cycleshard. You are given a complete undirected graph with $n$ nodes numbered from 1 to $n$. You are also given $k$ forbidden edges in this graph. You are asked to find the number of Hamiltonian cycles in this graph that do...
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Cycles (Hard) Description: Note that this is a harder version of the problem cycleseasy. You are given a complete undirected graph with $n$ nodes numbered from 1 to $n$. You are also given $k$ forbidden edges in this graph. You are asked to find the number of Hamiltonian cycles in this graph that don...
27,087
Cyclic Sightseeing Description: One sightseeing trip consists of $S$ places and exactly $S$ streets which connect them. He starts by travelling to one of these places by subway, with his moped on his back. Then he starts riding his moped to each place of the trip in turn, finally returning to where he ...
27,088
Cyclical Periods Description: Given a sequence of strings of lowercase letters (arbitrary ordering of letters in each string) and their positions on the number line, your task is to determine which letter represents the cycle with the longest period. The number line will start at 1 and will not be long...
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Cypher Decypher Description: Princess Peach is trying to organize the armies of Mushroom Kingdom to repel Bowser’s attack. However, her orders keep getting intercepted by Bowser’s top spy Mr. L. Peach has tried multiple encryption methods, but Mr. L has cleverly decrypted all attempts. However, Peach’s...
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D Fyrir Dreki Description: Daði Dreki is always practising on how to become more brave and next up for him is to see how brave he is in the world of mathematics. As everyone knows, only the most daring and bravest can find the roots of a second degree polynomial and thus Daði wants to become one of the...
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DA-Sort Description: You recently learned a new way to sort an array of numbers in your algorithms course. The algorithm sorts an array of numbers by repeatedly performing the Delete-and-Append operation. The Delete-and-Append operation consists of three steps: * Choose an element from the array. * D...
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DEX Save Description: Always one to dwell on the past, you begin to wonder what your chances actually were of succeeding with the saving throw, and discover that it is not immediately obvious – you had that bardic inspiration giving you a d6 bonus, but then you had disadvantage on the roll due to being...
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DJ Gigs Description: Doug James is an up-and-coming DJ from Graphland who’s had a tough time making it big. This all changed with the release of his latest EP Wiggly Waves, which is the first album in history to go both Platinum and Uranium. With his newfound popularity, Doug (a.k.a. DJ Polygon) needs ...
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DNA Description: Biologists have discovered a strange DNA molecule, best described as a sequence of $N$ characters from the set $\{ A, B\} $. An unlikely sequence of mutations has resulted in a DNA strand consisting only of $A$’s. Biologists found that very odd, so they began studying the mutations...
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DRM Messages Description: DRM Encryption is a new kind of encryption. Given an encrypted string (which we’ll call a DRM message), the decryption process involves three steps: Divide, Rotate and Merge. This process is described in the following example with the DRM message “EWPGAJRB”: – First, divide t...
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DVD Screensaver Description: You may remember old DVD screensavers where the logo bounces around the edges of the screen. Of course, the most satisfying moment is when the logo bounces off one of the corners of the screen. Johnny would like to know when the logo will collide with a corner of the scree...
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DVDs Description: Dezider is very unhappy as he just discovered that his DVDs got unsorted. Dezider is (occasionally) very organized and during one of his get-organized spells he numbered the DVDs from $1$ to $n$. He keeps the DVDs in a tall stack and he wants to have them sorted in increasing order by...
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Dacey the Dice Description: Dacey the Dice is lost in the twisted forest and needs help to find a way back home. Dacey the Dice moves by rolling over from one side to the next along dark and petrifying pathways. Dacey’s goal is to make a safe return to Dacey’s Home Sweet Home, which is a safeguarded by...
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