Problem ID stringlengths 2 6 | Problem Description stringlengths 0 7.52k | Rating float64 800 3.5k | math bool 2
classes | greedy bool 2
classes | implementation bool 2
classes | dp bool 2
classes | data structures bool 2
classes | constructive algorithms bool 2
classes | brute force bool 2
classes | binary search bool 2
classes | sortings bool 2
classes | graphs bool 2
classes | __index_level_0__ int64 3 9.98k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1950G | Vladislav has a playlist consisting of $$$n$$$ songs, numbered from $$$1$$$ to $$$n$$$. Song $$$i$$$ has genre $$$g_i$$$ and writer $$$w_i$$$. He wants to make a playlist in such a way that every pair of adjacent songs either have the same writer or are from the same genre (or both). He calls such a playlist exciting. ... | 1,900 | false | false | true | true | false | false | false | false | false | true | 575 |
417A | The finalists of the "Russian Code Cup" competition in 2214 will be the participants who win in one of the elimination rounds. The elimination rounds are divided into main and additional. Each of the main elimination rounds consists of _c_ problems, the winners of the round are the first _n_ people in the rating list. ... | 1,500 | true | false | true | true | false | false | false | false | false | false | 8,157 |
1547B | A string $$$s$$$ of length $$$n$$$ ($$$1 le n le 26$$$) is called alphabetical if it can be obtained using the following algorithm: first, write an empty string to $$$s$$$ (i.e. perform the assignment $$$s$$$xa0:= ""); then perform the next step $$$n$$$ times; at the $$$i$$$-th step take $$$i$$$-th lowercase letter ... | 800 | false | true | true | false | false | false | false | false | false | false | 2,912 |
1346I | Polycarp is developing a new version of an old video game "Pac-Man". Though he really enjoyed playing the original game, he didn't like some aspects of it, so he decided to alter the rules a bit. In Polycarp's version, you play as Pac-Man and you have to collect pellets scattered over the game world while avoiding dang... | 2,900 | false | false | false | true | false | false | false | false | false | false | 3,971 |
605A | Problem - 605A - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,600 | false | true | false | false | false | true | false | false | false | false | 7,426 |
1181C | Innokenty works at a flea market and sells some random stuff rare items. Recently he found an old rectangular blanket. It turned out that the blanket is split in $$$n cdot m$$$ colored pieces that form a rectangle with $$$n$$$ rows and $$$m$$$ columns. The colored pieces attracted Innokenty's attention so he immediatel... | 1,900 | false | false | true | true | false | false | true | false | false | false | 4,812 |
1927D | You are given an array $$$a$$$ of $$$n$$$ integers, and $$$q$$$ queries. Each query is represented by two integers $$$l$$$ and $$$r$$$ ($$$1 le l le r le n$$$). Your task is to find, for each query, two indices $$$i$$$ and $$$j$$$ (or determine that they do not exist) such that: $$$l le i le r$$$; $$$l le j le r$$$; ... | 1,300 | false | true | false | true | true | false | true | true | false | false | 727 |
380E | Problem - 380E - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,600 | false | false | false | false | true | false | false | false | false | false | 8,306 |
1043B | Bajtek, known for his unusual gifts, recently got an integer array $$$x_0, x_1, ldots, x_{k-1}$$$. Unfortunately, after a huge array-party with his extraordinary friends, he realized that he'd lost it. After hours spent on searching for a new toy, Bajtek found on the arrays producer's website another array $$$a$$$ of l... | 1,200 | false | false | true | false | false | false | false | false | false | false | 5,482 |
1805F2 | This is the hard version of the problem. It differs from the easy one only in constraints on $$$n$$$. You can make hacks only if you lock both versions. Let $$$a_1, a_2, ldots, a_n$$$ be an array of non-negative integers. Let $$$F(a_1, a_2, ldots, a_n)$$$ be the sorted in the non-decreasing order array of $$$n - 1$$$ s... | 3,100 | true | true | false | false | false | false | false | false | true | false | 1,443 |
521D | Vasya plays one very well-known and extremely popular MMORPG game. His game character has _k_ skill; currently the _i_-th of them equals to _a__i_. Also this game has a common rating table in which the participants are ranked according to the product of all the skills of a hero in the descending order. Vasya decided to... | 2,800 | false | true | false | false | false | false | false | false | false | false | 7,752 |
45C | There are _n_ people taking dancing lessons. Every person is characterized by his/her dancing skill _a__i_. At the beginning of the lesson they line up from left to right. While there is at least one couple of a boy and a girl in the line, the following process is repeated: the boy and girl who stand next to each other... | 1,900 | false | false | false | false | true | false | false | false | false | false | 9,757 |
1553F | Problem - 1553F - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - ... | 2,300 | true | false | false | false | true | false | false | false | false | false | 2,870 |
1426A | Vasya goes to visit his classmate Petya. Vasya knows that Petya's apartment number is $$$n$$$. There is only one entrance in Petya's house and the distribution of apartments is the following: the first floor contains $$$2$$$ apartments, every other floor contains $$$x$$$ apartments each. Apartments are numbered startin... | 800 | true | false | true | false | false | false | false | false | false | false | 3,539 |
254C | String _x_ is an anagram of string _y_, if we can rearrange the letters in string _x_ and get exact string _y_. For example, strings "DOG" and "GOD" are anagrams, so are strings "BABA" and "AABB", but strings "ABBAC" and "CAABA" are not. You are given two strings _s_ and _t_ of the same length, consisting of uppercase ... | 1,800 | false | true | false | false | false | false | false | false | false | false | 8,817 |
1372B | In Omkar's last class of math, he learned about the least common multiple, or $$$LCM$$$. $$$LCM(a, b)$$$ is the smallest positive integer $$$x$$$ which is divisible by both $$$a$$$ and $$$b$$$. Omkar, having a laudably curious mind, immediately thought of a problem involving the $$$LCM$$$ operation: given an integer $$... | 1,300 | true | true | false | false | false | false | false | false | false | false | 3,806 |
116B | Once upon a time there were several little pigs and several wolves on a two-dimensional grid of size _n_u2009Γu2009_m_. Each cell in this grid was either empty, containing one little pig, or containing one wolf. A little pig and a wolf are adjacent if the cells that they are located at share a side. The little pigs are... | 1,100 | false | true | true | false | false | false | false | false | false | false | 9,422 |
899C | Problem - 899C - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,300 | true | false | false | false | false | true | false | false | false | true | 6,150 |
1418A | You are playing a very popular game called Cubecraft. Initially, you have one stick and want to craft $$$k$$$ torches. One torch can be crafted using one stick and one coal. Hopefully, you've met a very handsome wandering trader who has two trade offers: exchange $$$1$$$ stick for $$$x$$$ sticks (you lose $$$1$$$ stic... | 1,000 | true | false | false | false | false | false | false | false | false | false | 3,594 |
1824B2 | This is the hard version of the problem. The only difference is that in this version $$$kle n$$$. You can make hacks only if both versions of the problem are solved. Chtholly and the floating islands. LuoTianyi now lives in a world with $$$n$$$ floating islands. The floating islands are connected by $$$n-1$$$ undirect... | 2,300 | true | false | false | false | false | false | false | false | false | false | 1,335 |
765F | Artsem is on vacation and wants to buy souvenirs for his two teammates. There are _n_ souvenir shops along the street. In _i_-th shop Artsem can buy one souvenir for _a__i_ dollars, and he cannot buy more than one souvenir in one shop. He doesn't want to introduce envy in his team, so he wants to buy two souvenirs with... | 3,100 | false | false | false | false | true | false | false | false | false | false | 6,725 |
978G | Petya studies at university. The current academic year finishes with $$$n$$$ special days. Petya needs to pass $$$m$$$ exams in those special days. The special days in this problem are numbered from $$$1$$$ to $$$n$$$. There are three values about each exam: $$$s_i$$$ β the day, when questions for the $$$i$$$-th exam ... | 1,700 | false | true | true | false | false | false | false | false | true | false | 5,812 |
1239A | Problem - 1239A - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - ... | 1,700 | true | false | false | true | false | false | false | false | false | false | 4,496 |
1082A | Vasya is reading a e-book. The file of the book consists of $$$n$$$ pages, numbered from $$$1$$$ to $$$n$$$. The screen is currently displaying the contents of page $$$x$$$, and Vasya wants to read the page $$$y$$$. There are two buttons on the book which allow Vasya to scroll $$$d$$$ pages forwards or backwards (but h... | 1,200 | true | false | true | false | false | false | false | false | false | false | 5,315 |
1721C | You are given an array $$$a_1, a_2, dots, a_n$$$, which is sorted in non-descending order. You decided to perform the following steps to create array $$$b_1, b_2, dots, b_n$$$: 1. Create an array $$$d$$$ consisting of $$$n$$$ arbitrary non-negative integers. 2. Set $$$b_i = a_i + d_i$$$ for each $$$b_i$$$. 3. Sort the ... | 1,400 | false | true | false | false | false | false | false | true | false | false | 1,957 |
734D | Anton likes to play chess. Also, he likes to do programming. That is why he decided to write the program that plays chess. However, he finds the game on 8 to 8 board to too simple, he uses an infinite one instead. The first task he faced is to check whether the king is in check. Anton doesn't know how to implement this... | 1,700 | false | false | true | false | false | false | false | false | false | false | 6,855 |
31D | Bob has a rectangular chocolate bar of the size _W_u2009Γu2009_H_. He introduced a cartesian coordinate system so that the point (0,u20090) corresponds to the lower-left corner of the bar, and the point (_W_,u2009_H_) corresponds to the upper-right corner. Bob decided to split the bar into pieces by breaking it. Each b... | 2,000 | false | false | true | false | false | false | false | false | false | false | 9,840 |
1676D | Timur's grandfather gifted him a chessboard to practice his chess skills. This chessboard is a grid $$$a$$$ with $$$n$$$ rows and $$$m$$$ columns with each cell having a non-negative integer written on it. Timur's challenge is to place a bishop on the board such that the sum of all cells attacked by the bishop is maxim... | 1,000 | false | true | true | false | false | false | true | false | false | false | 2,212 |
2022B | Karel is a salesman in a car dealership. The dealership has $$$n$$$ different models of cars. There are $$$a_i$$$ cars of the $$$i$$$-th model. Karel is an excellent salesperson and can convince customers to buy up to $$$x$$$ cars (of Karel's choice), as long as the cars are from different models. Determine the minimum... | 1,300 | true | true | false | false | false | false | false | true | false | false | 137 |
1054D | At a break Vanya came to the class and saw an array of $$$n$$$ $$$k$$$-bit integers $$$a_1, a_2, ldots, a_n$$$ on the board. An integer $$$x$$$ is called a $$$k$$$-bit integer if $$$0 leq x leq 2^k - 1$$$. Of course, Vanya was not able to resist and started changing the numbers written on the board. To ensure that no o... | 1,900 | false | true | true | false | false | false | false | false | false | false | 5,444 |
1881D | You are given an array $$$a$$$ consisting of $$$n$$$ positive integers. You can perform the following operation on it: 1. Choose a pair of elements $$$a_i$$$ and $$$a_j$$$ ($$$1 le i, j le n$$$ and $$$i eq j$$$); 2. Choose one of the divisors of the integer $$$a_i$$$, i.e., an integer $$$x$$$ such that $$$a_i bmod x =... | 1,300 | true | false | false | false | false | false | false | false | false | false | 1,001 |
1903D1 | This is the easy version of the problem. The only difference between the two versions is the constraint on $$$n$$$ and $$$q$$$, the memory and time limits. You can make hacks only if all versions of the problem are solved. Theofanis really likes to play with the bits of numbers. He has an array $$$a$$$ of size $$$n$$$ ... | 1,700 | false | true | false | false | false | false | true | true | false | false | 894 |
380D | The cinema theater hall in Sereja's city is _n_ seats lined up in front of one large screen. There are slots for personal possessions to the left and to the right of each seat. Any two adjacent seats have exactly one shared slot. The figure below shows the arrangement of seats and slots for _n_u2009=u20094. Today it's ... | 2,500 | true | false | false | false | false | false | false | false | false | false | 8,307 |
1776B | Vittorio is playing with his new LEGO Duplo bricks. All the bricks have the shape of a square cuboid with a $$$2 imes 2$$$ square base and a height of $$$1$$$. They can be arranged in the 3D space to build structures, provided that the following rules are met: 1. No two bricks can intersect, but they can touch on thei... | 2,200 | false | false | false | true | false | false | false | false | false | false | 1,627 |
1832F | Polycarp plays a computer game in a post-apocalyptic setting. The zombies have taken over the world, and Polycarp with a small team of survivors is defending against hordes trying to invade their base. The zombies are invading for $$$x$$$ minutes starting from minute $$$0$$$. There are $$$n$$$ entrances to the base, an... | 3,200 | false | false | false | true | false | false | false | true | false | false | 1,292 |
1957E | You are given an integer $$$n$$$. The function $$$C(i,k)$$$ represents the number of distinct ways you can select $$$k$$$ distinct numbers from the set {$$$1, 2, ldots, i$$$} and arrange them in a circle$$$^dagger$$$. Find the value of $$$$$$ sumlimits_{i=1}^n sumlimits_{j=1}^i left( C(i,j) bmod j ight). $$$$$$ Here, ... | 2,400 | true | false | false | true | false | false | true | false | false | false | 529 |
680B | There are _n_ cities in Bearland, numbered 1 through _n_. Cities are arranged in one long row. The distance between cities _i_ and _j_ is equal to _i_u2009-u2009_j_. Limak is a police officer. He lives in a city _a_. His job is to catch criminals. It's hard because he doesn't know in which cities criminals are. Though,... | 1,000 | false | false | true | false | false | true | false | false | false | false | 7,104 |
1481A | You were dreaming that you are traveling to a planet named Planetforces on your personal spaceship. Unfortunately, its piloting system was corrupted and now you need to fix it in order to reach Planetforces. Space can be represented as the $$$XY$$$ plane. You are starting at point $$$(0, 0)$$$, and Planetforces is loca... | 800 | false | true | false | false | false | false | false | false | false | false | 3,273 |
652A | The 9-th grade student Gabriel noticed a caterpillar on a tree when walking around in a forest after the classes. The caterpillar was on the height _h_1 cm from the ground. On the height _h_2 cm (_h_2u2009>u2009_h_1) on the same tree hung an apple and the caterpillar was crawling to the apple. Gabriel is interested whe... | 1,400 | true | false | true | false | false | false | false | false | false | false | 7,210 |
1349D | Slime and his $$$n$$$ friends are at a party. Slime has designed a game for his friends to play. At the beginning of the game, the $$$i$$$-th player has $$$a_i$$$ biscuits. At each second, Slime will choose a biscuit randomly uniformly among all $$$a_1 + a_2 + ldots + a_n$$$ biscuits, and the owner of this biscuit will... | 3,200 | true | false | false | false | false | false | false | false | false | false | 3,961 |
1093D | You are given an undirected unweighted graph consisting of $$$n$$$ vertices and $$$m$$$ edges. You have to write a number on each vertex of the graph. Each number should be $$$1$$$, $$$2$$$ or $$$3$$$. The graph becomes beautiful if for each edge the sum of numbers on vertices connected by this edge is odd. Calculate t... | 1,700 | false | false | false | false | false | false | false | false | false | true | 5,241 |
1113A | Sasha is a very happy guy, that's why he is always on the move. There are $$$n$$$ cities in the country where Sasha lives. They are all located on one straight line, and for convenience, they are numbered from $$$1$$$ to $$$n$$$ in increasing order. The distance between any two adjacent cities is equal to $$$1$$$ kilom... | 900 | true | true | false | true | false | false | false | false | false | false | 5,136 |
1216C | There is a white sheet of paper lying on a rectangle table. The sheet is a rectangle with its sides parallel to the sides of the table. If you will take a look from above and assume that the bottom left corner of the table has coordinates $$$(0, 0)$$$, and coordinate axes are left and bottom sides of the table, then th... | 1,700 | true | false | false | false | false | false | false | false | false | false | 4,595 |
27A | Problem - 27A - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - so... | 1,200 | false | false | true | false | false | false | false | false | true | false | 9,863 |
1237E | Recall that a binary search tree is a rooted binary tree, whose nodes each store a key and each have at most two distinguished subtrees, left and right. The key in each node must be greater than any key stored in the left subtree, and less than any key stored in the right subtree. The depth of a vertex is the number of... | 2,400 | true | false | false | true | false | false | false | false | false | false | 4,507 |
988C | You are given $$$k$$$ sequences of integers. The length of the $$$i$$$-th sequence equals to $$$n_i$$$. You have to choose exactly two sequences $$$i$$$ and $$$j$$$ ($$$i e j$$$) such that you can remove exactly one element in each of them in such a way that the sum of the changed sequence $$$i$$$ (its length will be ... | 1,400 | false | false | true | false | false | false | false | false | true | false | 5,761 |
1511B | You are given three integers $$$a$$$, $$$b$$$ and $$$c$$$. Find two positive integers $$$x$$$ and $$$y$$$ ($$$x > 0$$$, $$$y > 0$$$) such that: the decimal representation of $$$x$$$ without leading zeroes consists of $$$a$$$ digits; the decimal representation of $$$y$$$ without leading zeroes consists of $$$b$$$ digi... | 1,100 | true | false | false | false | false | true | false | false | false | false | 3,115 |
662E | Consider a regular Codeforces round consisting of three problems that uses dynamic scoring. You are given an almost final scoreboard. For each participant (including yourself), the time of the accepted submission for each of the problems is given. Also, for each solution you already know whether you are able to hack it... | 3,100 | false | true | false | true | false | false | true | false | false | false | 7,164 |
1729F | Given the string $$$s$$$ of decimal digits (0-9) of length $$$n$$$. A substring is a sequence of consecutive characters of a string. The substring of this string is defined by a pair of indexes β with its left and right ends. So, each pair of indexes ($$$l, r$$$), where $$$1 le l le r le n$$$, corresponds to a substrin... | 1,900 | true | false | false | false | false | false | false | false | false | false | 1,913 |
1393B | This year in Equestria was a year of plenty, so Applejack has decided to build some new apple storages. According to the advice of the farm designers, she chose to build two storages with non-zero area: one in the shape of a square and another one in the shape of a rectangle (which possibly can be a square as well). Ap... | 1,400 | false | true | true | false | true | true | false | false | false | false | 3,706 |
437C | On Children's Day, the child got a toy from Delayyy as a present. However, the child is so naughty that he can't wait to destroy the toy. The toy consists of _n_ parts and _m_ ropes. Each rope links two parts, but every pair of parts is linked by at most one rope. To split the toy, the child must remove all its parts. ... | 1,400 | false | true | false | false | false | false | false | false | true | true | 8,089 |
1468J | There are $$$n$$$ cities and $$$m$$$ bidirectional roads in Berland. The $$$i$$$-th road connects the cities $$$x_i$$$ and $$$y_i$$$, and has the speed limit $$$s_i$$$. The road network allows everyone to get from any city to any other city. The Berland Transport Ministry is planning a road reform. First of all, mainta... | 1,800 | false | true | false | false | false | false | false | false | false | true | 3,343 |
1809G | Consider a tournament with $$$n$$$ participants. The rating of the $$$i$$$-th participant is $$$a_i$$$. The tournament will be organized as follows. First of all, organizers will assign each participant an index from $$$1$$$ to $$$n$$$. All indices will be unique. Let $$$p_i$$$ be the participant who gets the index $$$... | 2,800 | true | false | false | true | false | false | false | false | false | false | 1,414 |
1209E2 | This is a harder version of the problem. The difference is only in constraints. You are given a rectangular $$$n imes m$$$ matrix $$$a$$$. In one move you can choose any column and cyclically shift elements in this column. You can perform this operation as many times as you want (possibly zero). You can perform this o... | 2,500 | false | true | false | true | false | false | false | false | true | false | 4,641 |
414A | It's holiday. Mashmokh and his boss, Bimokh, are playing a game invented by Mashmokh. In this game Mashmokh writes sequence of _n_ distinct integers on the board. Then Bimokh makes several (possibly zero) moves. On the first move he removes the first and the second integer from from the board, on the second move he rem... | 1,500 | false | false | false | false | false | true | false | false | false | false | 8,169 |
100H | Do you know the game Battleship? If no, look into Wikipedia article You are given the positions of ships on a 10u2009Γu200910 board for playing Battleship. According to the rules, the board should contain the following ships: one of size 4 (4u2009Γu20091 or 1u2009Γu20094 rectangle), two of size 3 (3u2009Γu20091 or 1u... | 2,100 | false | false | true | false | false | false | false | false | false | false | 9,482 |
920F | Problem - 920F - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,000 | false | false | false | false | true | false | true | false | false | false | 6,045 |
768G | Given a rooted tree with _n_ nodes. The Night King removes exactly one node from the tree and all the edges associated with it. Doing this splits the tree and forms a forest. The node which is removed is not a part of the forest. The root of a tree in the forest is the node in that tree which does not have a parent. We... | 3,300 | false | false | false | false | true | false | false | true | false | false | 6,707 |
1774H | Ecrade bought a deck of cards numbered from $$$1$$$ to $$$n$$$. Let the value of a permutation $$$a$$$ of length $$$n$$$ be $$$minlimits_{i = 1}^{n - k + 1} sumlimits_{j = i}^{i + k - 1}a_j$$$. Ecrade wants to find the most valuable one among all permutations of the cards. However, it seems a little difficult, so pleas... | 3,500 | false | false | false | false | false | true | false | false | false | false | 1,636 |
1557A | Ezzat has an array of $$$n$$$ integers (maybe negative). He wants to split it into two non-empty subsequences $$$a$$$ and $$$b$$$, such that every element from the array belongs to exactly one subsequence, and the value of $$$f(a) + f(b)$$$ is the maximum possible value, where $$$f(x)$$$ is the average of the subsequen... | 800 | true | false | false | false | false | false | true | false | true | false | 2,847 |
26B | Problem - 26B - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - so... | 1,400 | false | true | false | false | false | false | false | false | false | false | 9,867 |
735A | On the way to Rio de Janeiro Ostap kills time playing with a grasshopper he took with him in a special box. Ostap builds a line of length _n_ such that some cells of this line are empty and some contain obstacles. Then, he places his grasshopper to one of the empty cells and a small insect in another empty cell. The gr... | 800 | false | false | true | false | false | false | false | false | false | false | 6,852 |
1837B | Problem - 1837B - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - ... | 900 | false | true | false | false | false | false | false | false | false | false | 1,269 |
989E | The cool breeze blows gently, the flowing water ripples steadily."Flowing and passing like this, the water isn't gone ultimately; Waxing and waning like that, the moon doesn't shrink or grow eventually." "Everything is transient in a way and perennial in another." Kanno doesn't seem to make much sense out of Mino's iso... | 2,700 | false | false | false | true | false | false | false | false | false | false | 5,753 |
1774F2 | This is the hard version of the problem. The only difference between the two versions is the constraint on $$$n$$$ and $$$x$$$. You can make hacks only if both versions of the problem are solved. Little09 has been interested in magic for a long time, and it's so lucky that he meets a magician! The magician will perform... | 2,700 | false | false | true | false | true | false | true | true | false | false | 1,638 |
538F | Andrew skipped lessons on the subject 'Algorithms and Data Structures' for the entire term. When he came to the final test, the teacher decided to give him a difficult task as a punishment. The teacher gave Andrew an array of _n_ numbers _a_1, ..., _a__n_. After that he asked Andrew for each _k_ from 1 to _n_u2009-u200... | 2,200 | true | false | false | false | true | false | true | false | true | false | 7,683 |
1585G | Alice and Bob are two poachers who cut trees in a forest. A forest is a set of zero or more trees. A tree is a connected graph without cycles. A rooted tree has a special vertex called the root. The parent of a node $$$v$$$ is the next vertex on the shortest path from $$$v$$$ to the root. Children of vertex $$$v$$$ are... | 2,500 | false | false | false | true | false | false | false | false | false | true | 2,696 |
1876A | Pak Chanek is the chief of a village named Khuntien. On one night filled with lights, Pak Chanek has a sudden and important announcement that needs to be notified to all of the $$$n$$$ residents in Khuntien. First, Pak Chanek shares the announcement directly to one or more residents with a cost of $$$p$$$ for each pers... | 1,000 | false | true | false | false | false | false | false | false | true | false | 1,026 |
486D | As you know, an undirected connected graph with _n_ nodes and _n_u2009-u20091 edges is called a tree. You are given an integer _d_ and a tree consisting of _n_ nodes. Each node _i_ has a value _a__i_ associated with it. We call a set _S_ of tree nodes valid if following conditions are satisfied: 1. _S_ is non-empty. 2.... | 2,100 | true | false | false | true | false | false | false | false | false | false | 7,892 |
625C | People do many crazy things to stand out in a crowd. Some of them dance, some learn by heart rules of Russian language, some try to become an outstanding competitive programmers, while others collect funny math objects. Alis is among these collectors. Right now she wants to get one of _k_-special tables. In case you fo... | 1,300 | false | false | true | false | false | true | false | false | false | false | 7,331 |
1093G | You are given an array $$$a$$$ of $$$n$$$ points in $$$k$$$-dimensional space. Let the distance between two points $$$a_x$$$ and $$$a_y$$$ be $$$sum limits_{i = 1}^{k} a_{x, i} - a_{y, i}$$$ (it is also known as Manhattan distance). You have to process $$$q$$$ queries of the following two types: $$$1$$$ $$$i$$$ $$$b_1... | 2,300 | false | false | false | false | true | false | false | false | false | false | 5,238 |
610C | The semester is already ending, so Danil made an effort and decided to visit a lesson on harmony analysis to know how does the professor look like, at least. Danil was very bored on this lesson until the teacher gave the group a simple task: find 4 vectors in 4-dimensional space, such that every coordinate of every vec... | 1,800 | false | false | false | false | false | true | false | false | false | false | 7,404 |
264E | Squirrel Liss loves nuts. Liss asks you to plant some nut trees. There are _n_ positions (numbered 1 to _n_ from west to east) to plant a tree along a street. Trees grow one meter per month. At the beginning of each month you should process one query. The query is one of the following types: 1. Plant a tree of height _... | 3,000 | false | false | false | true | true | false | false | false | false | false | 8,774 |
1207B | You are given two matrices $$$A$$$ and $$$B$$$. Each matrix contains exactly $$$n$$$ rows and $$$m$$$ columns. Each element of $$$A$$$ is either $$$0$$$ or $$$1$$$; each element of $$$B$$$ is initially $$$0$$$. You may perform some operations with matrix $$$B$$$. During each operation, you choose any submatrix of $$$B$... | 1,200 | false | true | true | false | false | true | false | false | false | false | 4,660 |
981D | Mr Keks is a typical white-collar in Byteland. He has a bookshelf in his office with some books on it, each book has an integer positive price. Mr Keks defines the value of a shelf as the sum of books prices on it. Miraculously, Mr Keks was promoted and now he is moving into a new office. He learned that in the new off... | 1,900 | false | true | false | true | false | false | false | false | false | false | 5,797 |
461C | Appleman has a very big sheet of paper. This sheet has a form of rectangle with dimensions 1u2009Γu2009_n_. Your task is help Appleman with folding of such a sheet. Actually, you need to perform _q_ queries. Each query will have one of the following types: 1. Fold the sheet of paper at position _p__i_. After this query... | 2,200 | false | false | true | false | true | false | false | false | false | false | 7,994 |
1118D2 | The only difference between easy and hard versions is the constraints. Polycarp has to write a coursework. The coursework consists of $$$m$$$ pages. Polycarp also has $$$n$$$ cups of coffee. The coffee in the $$$i$$$-th cup Polycarp has $$$a_i$$$ caffeine in it. Polycarp can drink some cups of coffee (each one no more ... | 1,700 | false | true | false | false | false | false | false | true | false | false | 5,098 |
678B | Problem - 678B - Codeforces =============== xa0 ]( "Educational Codeforces Round 13") β the year of the calendar. Output Print the only integer _y_' β the next year after _y_ when the calendar will be the same. Note that you should find the first year after _y_ with the same calendar. Examples Input 2016 ... | 1,600 | false | false | true | false | false | false | false | false | false | false | 7,115 |
987B | Year 2118. Androids are in mass production for decades now, and they do all the work for humans. But androids have to go to school to be able to solve creative tasks. Just like humans before. It turns out that high school struggles are not gone. If someone is not like others, he is bullied. Vasya-8800 is an economy-cla... | 1,100 | true | false | false | false | false | false | false | false | false | false | 5,765 |
1020A | You are looking at the floor plan of the Summer Informatics School's new building. You were tasked with SIS logistics, so you really care about travel time between different locations: it is important to know how long it would take to get from the lecture room to the canteen, or from the gym to the server room. The bui... | 1,000 | true | false | false | false | false | false | false | false | false | false | 5,592 |
304B | Problem - 304B - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,300 | false | false | true | false | false | false | true | false | false | false | 8,617 |
1669C | Given an array $$$a=[a_1,a_2,dots,a_n]$$$ of $$$n$$$ positive integers, you can do operations of two types on it: 1. Add $$$1$$$ to every element with an odd index. In other words change the array as follows: $$$a_1 := a_1 +1, a_3 := a_3 + 1, a_5 := a_5+1, dots$$$. 2. Add $$$1$$$ to every element with an even index. In... | 800 | true | true | true | false | false | false | false | false | false | false | 2,263 |
1858A | Anna and Katie ended up in a secret laboratory. There are $$$a+b+c$$$ buttons in the laboratory. It turned out that $$$a$$$ buttons can only be pressed by Anna, $$$b$$$ buttons can only be pressed by Katie, and $$$c$$$ buttons can be pressed by either of them. Anna and Katie decided to play a game, taking turns pressin... | 800 | true | true | false | false | false | false | false | false | false | false | 1,137 |
1841B | The array $$$[a_1, a_2, dots, a_k]$$$ is called beautiful if it is possible to remove several (maybe zero) elements from the beginning of the array and insert all these elements to the back of the array in the same order in such a way that the resulting array is sorted in non-descending order. In other words, the array... | 1,000 | false | false | true | false | false | false | false | false | false | false | 1,244 |
1364D | # Ehabβs Last Corollary Input file: standard input Output file: standard output Time limit: 1 second Memory limit: 256 megabytes Given a connected undirected graph with n vertices and an integer k, you have to either: β’ either find an independent set that has exactly d k > 2 e vertices. β’ or find a simple cycle o... | 2,100 | false | true | true | false | false | true | false | false | false | true | 3,859 |
362A | A boy Petya loves chess very much. He even came up with a chess piece of his own, a semiknight. The semiknight can move in any of these four directions: 2 squares forward and 2 squares to the right, 2 squares forward and 2 squares to the left, 2 squares backward and 2 to the right and 2 squares backward and 2 to the le... | 1,500 | true | true | false | false | false | false | false | false | false | false | 8,387 |
912E | Problem - 912E - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,400 | true | false | false | false | false | false | false | true | false | false | 6,092 |
498E | Problem - 498E - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,700 | false | false | false | true | false | false | false | false | false | false | 7,840 |
1176C | You are given an array $$$a$$$ consisting of $$$n$$$ integers. Each $$$a_i$$$ is one of the six following numbers: $$$4, 8, 15, 16, 23, 42$$$. Your task is to remove the minimum number of elements to make this array good. An array of length $$$k$$$ is called good if $$$k$$$ is divisible by $$$6$$$ and it is possible to... | 1,300 | false | true | true | true | false | false | false | false | false | false | 4,836 |
478E | Problem - 478E - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,900 | false | false | false | false | false | false | true | false | true | false | 7,917 |
1064B | Colossal!xa0β exclaimed Hawk-nose.xa0β A programmer! That's exactly what we are looking for. Arkadi and Boris Strugatsky. Monday starts on Saturday Reading the book "Equations of Mathematical Magic" Roman Oira-Oira and Cristobal Junta found an interesting equation: $$$a - (a oplus x) - x = 0$$$ for some given $$$a$$$, ... | 1,200 | true | false | false | false | false | false | false | false | false | false | 5,389 |
177D2 | The Smart Beaver from ABBYY invented a new message encryption method and now wants to check its performance. Checking it manually is long and tiresome, so he decided to ask the ABBYY Cup contestants for help. A message is a sequence of _n_ integers _a_1,u2009_a_2,u2009...,u2009_a__n_. Encryption uses a key which is a s... | 1,500 | false | false | false | false | true | false | false | false | false | false | 9,147 |
12A | There is a very secret base in Potatoland where potato mash is made according to a special recipe. The neighbours from Porridgia decided to seize this recipe and to sell it to Pilauland. For this mission they have been preparing special agent Pearlo for many years. When, finally, Pearlo learned all secrets of espionage... | 800 | false | false | true | false | false | false | false | false | false | false | 9,935 |
1073A | You are given a string $$$s$$$, consisting of $$$n$$$ lowercase Latin letters. A substring of string $$$s$$$ is a continuous segment of letters from $$$s$$$. For example, "defor" is a substring of "codeforces" and "fors" is not. The length of the substring is the number of letters in it. Let's call some string of lengt... | 1,000 | false | false | true | false | false | false | false | false | false | false | 5,353 |
1538G | Polycarp has $$$x$$$ of red and $$$y$$$ of blue candies. Using them, he wants to make gift sets. Each gift set contains either $$$a$$$ red candies and $$$b$$$ blue candies, or $$$a$$$ blue candies and $$$b$$$ red candies. Any candy can belong to at most one gift set. Help Polycarp to find the largest number of gift set... | 2,100 | true | true | false | false | false | false | false | true | false | false | 2,949 |
1919C | You are given an array $$$a$$$ of size $$$n$$$. You will do the following process to calculate your penalty: 1. Split array $$$a$$$ into two (possibly empty) subsequences$$$^dagger$$$ $$$s$$$ and $$$t$$$ such that every element of $$$a$$$ is either in $$$s$$$ or $$$t^ddagger$$$. 2. For an array $$$b$$$ of size $$$m$$$,... | 1,400 | false | true | false | true | true | false | false | false | false | false | 779 |
1599I | Problem - 1599I - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - ... | 2,700 | false | false | false | false | true | false | false | false | false | true | 2,656 |
1201E1 | This problem only differs from the next problem in constraints. This is an interactive problem. Alice and Bob are playing a game on the chessboard of size $$$n imes m$$$ where $$$n$$$ and $$$m$$$ are even. The rows are numbered from $$$1$$$ to $$$n$$$ and the columns are numbered from $$$1$$$ to $$$m$$$. There are two... | 2,900 | false | false | false | false | false | false | false | false | false | true | 4,691 |
1239E | Kolya has a turtle and a field of size $$$2 imes n$$$. The field rows are numbered from $$$1$$$ to $$$2$$$ from top to bottom, while the columns are numbered from $$$1$$$ to $$$n$$$ from left to right. Suppose in each cell of the field there is a lettuce leaf. The energy value of lettuce leaf in row $$$i$$$ and column... | 3,100 | false | false | true | true | false | false | false | false | false | false | 4,492 |
246B | Problem - 246B - Codeforces =============== xa0 ]( --- Finished β Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,300 | true | true | false | false | false | false | false | false | false | false | 8,847 |
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