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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
413E | The last product of the R2 company in the 2D games' field is a new revolutionary algorithm of searching for the shortest path in a 2u2009×u2009_n_ maze. Imagine a maze that looks like a 2u2009×u2009_n_ rectangle, divided into unit squares. Each unit square is either an empty cell or an obstacle. In one unit of time, a ... | 2,200 | false | false | false | false | true | false | false | false | false | false | 8,170 |
449B | Jzzhu is the president of country A. There are _n_ cities numbered from 1 to _n_ in his country. City 1 is the capital of A. Also there are _m_ roads connecting the cities. One can go from city _u__i_ to _v__i_ (and vise versa) using the _i_-th road, the length of this road is _x__i_. Finally, there are _k_ train route... | 2,000 | false | true | false | false | false | false | false | false | false | true | 8,043 |
1630B | Given an array $$$a$$$ of $$$n$$$ integers, find a range of values $$$[x, y]$$$ ($$$x le y$$$), and split $$$a$$$ into exactly $$$k$$$ ($$$1 le k le n$$$) subarrays in such a way that: Each subarray is formed by several continuous elements of $$$a$$$, that is, it is equal to $$$a_l, a_{l+1}, ldots, a_r$$$ for some $$$... | 1,800 | false | true | false | false | true | true | false | true | false | false | 2,465 |
1151C | Nazar, a student of the scientific lyceum of the Kingdom of Kremland, is known for his outstanding mathematical abilities. Today a math teacher gave him a very difficult task. Consider two infinite sets of numbers. The first set consists of odd positive numbers ($$$1, 3, 5, 7, ldots$$$), and the second set consists of ... | 1,800 | true | false | false | false | false | true | false | false | false | false | 4,960 |
1777E | You will be given a weighted directed graph of $$$n$$$ nodes and $$$m$$$ directed edges, where the $$$i$$$-th edge has a weight of $$$w_i$$$ ($$$1 le i le m$$$). You need to reverse some edges of this graph so that there is at least one node in the graph from which every other node is reachable. The cost of these rever... | 2,200 | false | false | false | false | false | false | false | true | false | true | 1,610 |
2004B | There are $$$100$$$ rooms arranged in a row and $$$99$$$ doors between them; the $$$i$$$-th door connects rooms $$$i$$$ and $$$i+1$$$. Each door can be either locked or unlocked. Initially, all doors are unlocked. We say that room $$$x$$$ is reachable from room $$$y$$$ if all doors between them are unlocked. You know t... | 1,000 | false | true | false | false | false | false | true | false | false | false | 230 |
215B | The World Programming Olympics Medal is a metal disk, consisting of two parts: the first part is a ring with outer radius of _r_1 cm, inner radius of _r_2 cm, (0u2009<u2009_r_2u2009<u2009_r_1) made of metal with density _p_1 g/cm3. The second part is an inner disk with radius _r_2 cm, it is made of metal with density _... | 1,300 | true | true | false | false | false | false | false | false | false | false | 8,980 |
1644D | There is a sheet of paper that can be represented with a grid of size $$$n imes m$$$: $$$n$$$ rows and $$$m$$$ columns of cells. All cells are colored in white initially. $$$q$$$ operations have been applied to the sheet. The $$$i$$$-th of them can be described as follows: $$$x_i$$$ $$$y_i$$$xa0— choose one of $$$k$$... | 1,700 | true | false | true | false | true | false | false | false | false | false | 2,398 |
1428E | There are some rabbits in Singapore Zoo. To feed them, Zookeeper bought $$$n$$$ carrots with lengths $$$a_1, a_2, a_3, ldots, a_n$$$. However, rabbits are very fertile and multiply very quickly. Zookeeper now has $$$k$$$ rabbits and does not have enough carrots to feed all of them. To solve this problem, Zookeeper deci... | 2,200 | true | true | false | false | true | false | false | true | true | false | 3,521 |
593E | Gosha's universe is a table consisting of _n_ rows and _m_ columns. Both the rows and columns are numbered with consecutive integers starting with 1. We will use (_r_,u2009_c_) to denote a cell located in the row _r_ and column _c_. Gosha is often invited somewhere. Every time he gets an invitation, he first calculates... | 2,400 | false | false | false | true | false | false | false | false | false | false | 7,473 |
909F | Problem - 909F - Codeforces =============== xa0 ]( --- Finished → Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 2,500 | false | false | false | false | false | true | false | false | false | false | 6,107 |
1889C1 | The only differences between the two versions of this problem are the constraint on $$$k$$$, the time limit and the memory limit. You can make hacks only if all versions of the problem are solved. Doremy lives in a rainy country consisting of $$$n$$$ cities numbered from $$$1$$$ to $$$n$$$. The weather broadcast predic... | 2,000 | false | true | false | true | true | false | true | false | true | false | 964 |
1495C | There are many sunflowers in the Garden of the Sun. Garden of the Sun is a rectangular table with $$$n$$$ rows and $$$m$$$ columns, where the cells of the table are farmlands. All of the cells grow a sunflower on it. Unfortunately, one night, the lightning stroke some (possibly zero) cells, and sunflowers on those cell... | 2,300 | false | false | false | false | false | true | false | false | false | true | 3,194 |
1721E | You are given a string $$$s$$$, consisting of lowercase Latin letters. You are asked $$$q$$$ queries about it: given another string $$$t$$$, consisting of lowercase Latin letters, perform the following steps: 1. concatenate $$$s$$$ and $$$t$$$; 2. calculate the prefix function of the resulting string $$$s+t$$$; 3. prin... | 2,200 | false | false | false | true | false | false | false | false | false | false | 1,955 |
65C | Brothers Fred and George Weasley once got into the sporting goods store and opened a box of Quidditch balls. After long and painful experiments they found out that the Golden Snitch is not enchanted at all. It is simply a programmed device. It always moves along the same trajectory, which is a polyline with vertices at... | 2,100 | false | false | false | false | false | false | false | true | false | false | 9,644 |
1385C | You are given an array $$$a$$$ consisting of $$$n$$$ integers. You have to find the length of the smallest (shortest) prefix of elements you need to erase from $$$a$$$ to make it a good array. Recall that the prefix of the array $$$a=[a_1, a_2, dots, a_n]$$$ is a subarray consisting several first elements: the prefix o... | 1,200 | false | true | false | false | false | false | false | false | false | false | 3,745 |
1989C | A movie company has released $$$2$$$ movies. These $$$2$$$ movies were watched by $$$n$$$ people. For each person, we know their attitude towards the first movie (liked it, neutral, or disliked it) and towards the second movie. If a person is asked to leave a review for the movie, then: if that person liked the movie,... | 1,400 | true | true | false | false | false | false | false | false | false | false | 339 |
1832E | Recall that the binomial coefficient $$$binom{x}{y}$$$ is calculated as follows ($$$x$$$ and $$$y$$$ are non-negative integers): if $$$x < y$$$, then $$$binom{x}{y} = 0$$$; otherwise, $$$binom{x}{y} = frac{x!}{y! cdot (x-y)!}$$$. You are given an array $$$a_1, a_2, dots, a_n$$$ and an integer $$$k$$$. You have to cal... | 2,200 | false | false | false | true | false | false | true | false | false | false | 1,293 |
774B | Stepan is a very experienced olympiad participant. He has _n_ cups for Physics olympiads and _m_ cups for Informatics olympiads. Each cup is characterized by two parameters — its significance _c__i_ and width _w__i_. Stepan decided to expose some of his cups on a shelf with width _d_ in such a way, that: there is at l... | 2,100 | false | false | false | false | true | false | false | true | false | false | 6,680 |
1047B | Problem - 1047B - Codeforces =============== xa0 ]( --- Finished → 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 | true | false | false | false | false | false | false | false | false | false | 5,456 |
1846D | Rudolph drew a beautiful Christmas tree and decided to print the picture. However, the ink in the cartridge often runs out at the most inconvenient moment. Therefore, Rudolph wants to calculate in advance how much green ink he will need. The tree is a vertical trunk with identical triangular branches at different heigh... | 1,200 | true | false | false | false | false | true | false | false | false | false | 1,205 |
235C | Some days ago, WJMZBMR learned how to answer the query "how many times does a string _x_ occur in a string _s_" quickly by preprocessing the string _s_. But now he wants to make it harder. So he wants to ask "how many consecutive substrings of _s_ are cyclical isomorphic to a given string _x_". You are given string _s_... | 2,700 | false | false | false | false | true | false | false | false | false | false | 8,894 |
1185A | Polycarp decided to relax on his weekend and visited to the performance of famous ropewalkers: Agafon, Boniface and Konrad. The rope is straight and infinite in both directions. At the beginning of the performance, Agafon, Boniface and Konrad are located in positions $$$a$$$, $$$b$$$ and $$$c$$$ respectively. At the en... | 800 | true | false | false | false | false | false | false | false | false | false | 4,780 |
1294E | You are given a rectangular matrix of size $$$n imes m$$$ consisting of integers from $$$1$$$ to $$$2 cdot 10^5$$$. In one move, you can: choose any element of the matrix and change its value to any integer between $$$1$$$ and $$$n cdot m$$$, inclusive; take any column and shift it one cell up cyclically (see the ex... | 1,900 | true | true | true | false | false | false | false | false | false | false | 4,225 |
2005B2 | This is the hard version of the problem. The only differences between the two versions are the constraints on $$$m$$$ and $$$q$$$. In this version, $$$m, q le 10^5$$$. You can make hacks only if both versions of the problem are solved. Narek and Tsovak were busy preparing this round, so they have not managed to do thei... | 1,200 | true | true | false | false | false | false | false | true | true | false | 222 |
1579E1 | Enter Register HOME TOP CATALOG CONTESTS GYM PROBLEMSET GROUPS RATING EDU API CALENDAR HELP RAYAN Codeforces Round 744 (Div. 3) Finished → Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If... | 1,000 | true | true | false | false | false | true | false | false | false | false | 2,737 |
1906L | Construct a parentheses sequence consisting of $$$N$$$ characters such that it is balanced and the length of its longest palindromic subsequence (LPS) is exactly $$$K$$$. Determine whether such a construction is possible. If there are several possible sequences, construct any of them. A parentheses sequence consists of... | 2,500 | false | false | false | false | false | true | false | false | false | false | 866 |
201B | A widely known among some people Belarusian sport programmer Yura possesses lots of information about cars. That is why he has been invited to participate in a game show called "Guess That Car!". The game show takes place on a giant parking lot, which is 4_n_ meters long from north to south and 4_m_ meters wide from we... | 1,800 | true | false | false | false | false | false | false | false | false | false | 9,038 |
1916H1 | Problem - 1916H1 - Codeforces =============== xa0 time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output This is the easy version of the problem. The only differences between the two versions of this problem are the constraints on $$$k$$$. You can ma... | 2,700 | true | false | false | true | false | false | true | false | false | false | 796 |
125A | Problem - 125A - Codeforces =============== xa0 . Output Print two non-negative space-separated integers _a_ and _b_, where _a_ is the numbers of feet and _b_ is the number of inches. Examples Input 42 Output 1 2 Input 5 Output 0 2 | 1,400 | true | false | false | false | false | false | false | false | false | false | 9,382 |
1525E | Monocarp is playing a game "Assimilation IV". In this game he manages a great empire: builds cities and conquers new lands. Monocarp's empire has $$$n$$$ cities. In order to conquer new lands he plans to build one Monument in each city. The game is turn-based and, since Monocarp is still amateur, he builds exactly one ... | 2,100 | true | false | false | true | false | false | false | false | false | false | 3,038 |
1840C | Dima Vatrushin is a math teacher at school. He was sent on vacation for $$$n$$$ days for his good work. Dima has long dreamed of going to a ski resort, so he wants to allocate several consecutive days and go skiing. Since the vacation requires careful preparation, he will only go for at least $$$k$$$ days. You are give... | 1,000 | true | false | false | false | false | false | false | false | false | false | 1,251 |
1517G | At the foot of Liyushan Mountain, $$$n$$$ tents will be carefully arranged to provide accommodation for those who are willing to experience the joy of approaching nature, the tranquility of the night, and the bright starry sky. The $$$i$$$-th tent is located at the point of $$$(x_i, y_i)$$$ and has a weight of $$$w_i$$... | 3,300 | false | false | false | false | false | true | false | false | false | true | 3,071 |
1108D | You have a garland consisting of $$$n$$$ lamps. Each lamp is colored red, green or blue. The color of the $$$i$$$-th lamp is $$$s_i$$$ ('R', 'G' and 'B' — colors of lamps in the garland). You have to recolor some lamps in this garland (recoloring a lamp means changing its initial color to another) in such a way that th... | 1,400 | false | true | false | true | false | true | false | false | false | false | 5,159 |
1725L | Pak Chanek is participating in a lemper cooking competition. In the competition, Pak Chanek has to cook lempers with $$$N$$$ stoves that are arranged sequentially from stove $$$1$$$ to stove $$$N$$$. Initially, stove $$$i$$$ has a temperature of $$$A_i$$$ degrees. A stove can have a negative temperature. Pak Chanek rea... | 2,400 | false | false | false | false | true | false | false | false | false | false | 1,935 |
677A | Vanya and his friends are walking along the fence of height _h_ and they do not want the guard to notice them. In order to achieve this the height of each of the friends should not exceed _h_. If the height of some person is greater than _h_ he can bend down and then he surely won't be noticed by the guard. The height ... | 800 | false | false | true | false | false | false | false | false | false | false | 7,121 |
1494B | Berland crossword is a puzzle that is solved on a square grid with $$$n$$$ rows and $$$n$$$ columns. Initially all the cells are white. To solve the puzzle one has to color some cells on the border of the grid black in such a way that: exactly $$$U$$$ cells in the top row are black; exactly $$$R$$$ cells in the right... | 1,400 | false | true | true | false | false | false | true | false | false | false | 3,201 |
449A | Jzzhu has a big rectangular chocolate bar that consists of _n_u2009×u2009_m_ unit squares. He wants to cut this bar exactly _k_ times. Each cut must meet the following requirements: each cut should be straight (horizontal or vertical); each cut should go along edges of unit squares (it is prohibited to divide any uni... | 1,700 | true | true | false | false | false | false | false | false | false | false | 8,044 |
833E | It is well-known that the best decoration for a flower bed in Sweetland are vanilla muffins. Seedlings of this plant need sun to grow up. Slastyona has _m_ seedlings, and the _j_-th seedling needs at least _k__j_ minutes of sunlight to grow up. Most of the time it's sunny in Sweetland, but sometimes some caramel clouds... | 3,400 | false | false | false | true | true | false | false | false | true | false | 6,430 |
2006F | Sadly, Dora poured the paint when painting the class mural. Dora considers the mural as the matrix $$$b$$$ of size $$$n imes n$$$. Initially, $$$b_{i,j} = 0$$$ for all $$$1 le i, j le n$$$. Dora has only two brushes which have two different colors. In one operation, she can paint the matrix with one of two brushes: T... | 3,500 | false | false | true | false | false | true | true | false | false | true | 212 |
1284B | A sequence $$$a = [a_1, a_2, ldots, a_l]$$$ of length $$$l$$$ has an ascent if there exists a pair of indices $$$(i, j)$$$ such that $$$1 le i < j le l$$$ and $$$a_i < a_j$$$. For example, the sequence $$$[0, 2, 0, 2, 0]$$$ has an ascent because of the pair $$$(1, 4)$$$, but the sequence $$$[4, 3, 3, 3, 1]$$$ doesn't h... | 1,400 | false | false | true | true | true | false | false | true | true | false | 4,273 |
272B | Problem - 272B - Codeforces =============== xa0 ]( --- Finished → Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,400 | true | false | true | false | false | false | false | false | false | false | 8,745 |
1851B | You have an array of integers $$$a$$$ of length $$$n$$$. You can apply the following operation to the given array: Swap two elements $$$a_i$$$ and $$$a_j$$$ such that $$$i eq j$$$, $$$a_i$$$ and $$$a_j$$$ are either both even or both odd. Determine whether it is possible to sort the array in non-decreasing order by p... | 800 | false | true | false | false | false | false | false | false | true | false | 1,173 |
1949I | You are given $$$n$$$ disks in the plane. The center of each disk has integer coordinates, and the radius of each disk is a positive integer. No two disks overlap in a region of positive area, but it is possible for disks to be tangent to each other. Your task is to determine whether it is possible to change the radii ... | 1,800 | false | false | false | false | false | false | false | false | false | true | 584 |
260A | Problem - 260A - Codeforces =============== xa0 ]( --- Finished → Virtual participation Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests. If you've seen these problems, a virtual contest is not for you - s... | 1,400 | true | false | true | false | false | false | false | false | false | false | 8,795 |
1488G | Problem - 1488G - Codeforces =============== xa0 . The cost of painting is the number of pairs $$$(x, y)$$$ such that $$$y bmod x = 0$$$, $$$y$$$ is red and $$$x$$$ is blue. For each $$$k in | 2,500 | false | true | false | false | true | false | false | false | false | false | 3,233 |
470A | Problem - 470A - Codeforces =============== xa0 points on each side. The formula is _H__n_u2009=u20093·_n_·(_n_u2009+u20091)u2009+u20091. You are given _n_; calculate _n_-th element of the sequence. Input The only line of input contains an integer _n_ (0u2009≤u2009_n_u2009≤u20099). Output Output the _n_-t... | 1,400 | false | false | true | false | false | false | false | false | false | false | 7,960 |
547B | Problem - 547B - Codeforces =============== xa0 ]( --- Finished → 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... | 1,900 | false | false | false | true | true | false | false | true | false | false | 7,651 |
1552B | The Olympic Games have just started and Federico is eager to watch the marathon race. There will be $$$n$$$ athletes, numbered from $$$1$$$ to $$$n$$$, competing in the marathon, and all of them have taken part in $$$5$$$ important marathons, numbered from $$$1$$$ to $$$5$$$, in the past. For each $$$1le ile n$$$ and $... | 1,500 | false | true | false | false | false | false | false | false | true | true | 2,883 |
1630E | Given a cyclic array $$$a$$$ of size $$$n$$$, where $$$a_i$$$ is the value of $$$a$$$ in the $$$i$$$-th position, there may be repeated values. Let us define that a permutation of $$$a$$$ is equal to another permutation of $$$a$$$ if and only if their values are the same for each position $$$i$$$ or we can transform th... | 2,900 | true | false | false | false | false | false | false | false | false | false | 2,462 |
720C | Today Peter has got an additional homework for tomorrow. The teacher has given three integers to him: _n_, _m_ and _k_, and asked him to mark one or more squares on a square grid of size _n_u2009×u2009_m_. The marked squares must form a connected figure, and there must be exactly _k_ triples of marked squares that form... | 3,100 | false | false | false | false | false | true | false | false | false | false | 6,935 |
903B | Vova is again playing some computer game, now an RPG. In the game Vova's character received a quest: to slay the fearsome monster called Modcrab. After two hours of playing the game Vova has tracked the monster and analyzed its tactics. The Modcrab has _h_2 health points and an attack power of _a_2. Knowing that, Vova ... | 1,200 | false | true | true | false | false | false | false | false | false | false | 6,133 |
110A | Problem - 110A - Codeforces =============== xa0 ]( --- Finished → 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... | 800 | false | false | true | false | false | false | false | false | false | false | 9,444 |
285B | Petya and Vasya are playing a game. Petya's got _n_ non-transparent glasses, standing in a row. The glasses' positions are indexed with integers from 1 to _n_ from left to right. Note that the positions are indexed but the glasses are not. First Petya puts a marble under the glass in position _s_. Then he performs some... | 1,200 | false | false | true | false | false | false | false | false | false | false | 8,695 |
629E | Famil Door’s City map looks like a tree (undirected connected acyclic graph) so other people call it Treeland. There are _n_ intersections in the city connected by _n_u2009-u20091 bidirectional roads. There are _m_ friends of Famil Door living in the city. The _i_-th friend lives at the intersection _u__i_ and works at... | 2,300 | false | false | false | true | true | false | false | false | false | false | 7,305 |
711E | ZS the Coder has recently found an interesting concept called the Birthday Paradox. It states that given a random set of 23 people, there is around 50% chance that some two of them share the same birthday. ZS the Coder finds this very interesting, and decides to test this with the inhabitants of Udayland. In Udayland, ... | 2,300 | true | false | false | false | false | false | false | false | false | false | 6,972 |
1935A | Congratulations, you have been accepted to the Master's Assistance Center! However, you were extremely bored in class and got tired of doing nothing, so you came up with a game for yourself. You are given a string $$$s$$$ and an even integer $$$n$$$. There are two types of operations that you can apply to it: 1. Add th... | 800 | false | false | false | false | false | true | false | false | false | false | 674 |
1848A | Vika and her friends went shopping in a mall, which can be represented as a rectangular grid of rooms with sides of length $$$n$$$ and $$$m$$$. Each room has coordinates $$$(a, b)$$$, where $$$1 le a le n, 1 le b le m$$$. Thus we call a hall with coordinates $$$(c, d)$$$ a neighbouring for it if $$$a - c + b - d = 1$$$... | 900 | true | false | false | false | false | false | false | false | false | false | 1,194 |
1879A | Monocarp organizes a weightlifting competition. There are $$$n$$$ athletes participating in the competition, the $$$i$$$-th athlete has strength $$$s_i$$$ and endurance $$$e_i$$$. The $$$1$$$-st athlete is Monocarp's friend Polycarp, and Monocarp really wants Polycarp to win. The competition will be conducted as follow... | 800 | false | true | false | false | false | false | false | false | false | false | 1,010 |
1580D | Alice has an integer sequence $$$a$$$ of length $$$n$$$ and all elements are different. She will choose a subsequence of $$$a$$$ of length $$$m$$$, and defines the value of a subsequence $$$a_{b_1},a_{b_2},ldots,a_{b_m}$$$ as $$$$$$sum_{i = 1}^m (m cdot a_{b_i}) - sum_{i = 1}^m sum_{j = 1}^m f(min(b_i, b_j), max(b_i, b... | 2,900 | false | true | false | true | false | false | true | false | false | false | 2,730 |
1934A | Given an array $$$a$$$ of $$$n$$$ elements, find the maximum value of the expression: $$$$$$a_i - a_j + a_j - a_k + a_k - a_l + a_l - a_i$$$$$$ where $$$i$$$, $$$j$$$, $$$k$$$, and $$$l$$$ are four distinct indices of the array $$$a$$$, with $$$1 le i, j, k, l le n$$$. Here $$$x$$$ denotes the absolute value of $$$x$$$... | 800 | true | true | false | false | false | false | false | false | false | false | 680 |
335D | You are given _n_ rectangles, labeled 1 through _n_. The corners of rectangles have integer coordinates and their edges are parallel to the _Ox_ and _Oy_ axes. The rectangles may touch each other, but they do not overlap (that is, there are no points that belong to the interior of more than one rectangle). Your task is... | 2,400 | false | false | false | true | false | false | true | false | false | false | 8,495 |
1497E1 | This is the easy version of the problem. The only difference is that in this version $$$k = 0$$$. There is an array $$$a_1, a_2, ldots, a_n$$$ of $$$n$$$ positive integers. You should divide it into a minimal number of continuous segments, such that in each segment there are no two numbers (on different positions), who... | 1,700 | true | true | false | true | true | false | false | false | false | false | 3,183 |
1304C | Gildong owns a bulgogi restaurant. The restaurant has a lot of customers, so many of them like to make a reservation before visiting it. Gildong tries so hard to satisfy the customers that he even memorized all customers' preferred temperature ranges! Looking through the reservation list, he wants to satisfy all custom... | 1,500 | false | true | true | true | false | false | false | false | true | false | 4,169 |
1257G | You are given an integer $$$x$$$ represented as a product of $$$n$$$ its prime divisors $$$p_1 cdot p_2, cdot ldots cdot p_n$$$. Let $$$S$$$ be the set of all positive integer divisors of $$$x$$$ (including $$$1$$$ and $$$x$$$ itself). We call a set of integers $$$D$$$ good if (and only if) there is no pair $$$a in D$$... | 2,600 | true | true | false | false | false | false | false | false | false | false | 4,395 |
431E | One day two students, Grisha and Diana, found themselves in the university chemistry lab. In the lab the students found _n_ test tubes with mercury numbered from 1 to _n_ and decided to conduct an experiment. The experiment consists of _q_ steps. On each step, one of the following actions occurs: 1. Diana pours all the... | 2,200 | false | false | false | false | true | false | false | true | false | false | 8,115 |
1491D | There is a new attraction in Singapore Zoo: The Infinite Zoo. The Infinite Zoo can be represented by a graph with an infinite number of vertices labeled $$$1,2,3,ldots$$$. There is a directed edge from vertex $$$u$$$ to vertex $$$u+v$$$ if and only if $$$u&v=v$$$, where $$$&$$$ denotes the — the number of queries. The ... | 1,800 | true | true | false | true | false | true | false | false | false | false | 3,219 |
1282A | Polycarp lives on the coordinate axis $$$Ox$$$ and travels from the point $$$x=a$$$ to $$$x=b$$$. It moves uniformly rectilinearly at a speed of one unit of distance per minute. On the axis $$$Ox$$$ at the point $$$x=c$$$ the base station of the mobile operator is placed. It is known that the radius of its coverage is ... | 900 | true | false | true | false | false | false | false | false | false | false | 4,286 |
309E | Information technologies are developing and are increasingly penetrating into all spheres of human activity. Incredible as it is, the most modern technology are used in farming! A large farm has a meadow with grazing sheep. Overall there are _n_ sheep and each of them contains a unique number from 1 to _n_ — because th... | 2,900 | false | true | false | false | false | false | false | true | false | false | 8,603 |
1384A | The length of the longest common prefix of two strings $$$s = s_1 s_2 ldots s_n$$$ and $$$t = t_1 t_2 ldots t_m$$$ is defined as the maximum integer $$$k$$$ ($$$0 le k le min(n,m)$$$) such that $$$s_1 s_2 ldots s_k$$$ equals $$$t_1 t_2 ldots t_k$$$. Koa the Koala initially has $$$n+1$$$ strings $$$s_1, s_2, dots, s_{n+... | 1,200 | false | true | false | false | false | true | false | false | false | false | 3,750 |
1658D2 | This is the hard version of the problem. The difference in the constraints between both versions are colored below in red. You can make hacks only if all versions of the problem are solved. Marin and Gojou are playing hide-and-seek with an array. Gojou initially perform the following steps: First, Gojou chooses $$$2$$... | 2,300 | true | false | false | false | true | false | true | false | false | false | 2,335 |
1842D | Tell a story about me and my animal friends. Tenzing has $$$n$$$ animal friends. He numbers them from $$$1$$$ to $$$n$$$. One day Tenzing wants to play with his animal friends. To do so, Tenzing will host several games. In one game, he will choose a set $$$S$$$ which is a subset of $$${1,2,3,...,n}$$$ and choose an int... | 1,900 | false | true | false | false | false | true | false | false | false | true | 1,236 |
506E | Problem - 506E - Codeforces =============== xa0 ]( --- Finished → 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... | 3,000 | false | false | false | true | false | false | false | false | false | false | 7,817 |
60D | Problem - 60D - Codeforces =============== xa0 can transfer laugh to other lawn (say, _j_) if there exists an integer (say, _b_) such, that some permutation of numbers _a_ | 2,500 | true | false | false | false | false | false | true | false | false | false | 9,672 |
1034E | Little C loves number «3» very much. He loves all things about it. Now he is interested in the following problem: There are two arrays of $$$2^n$$$ intergers $$$a_0,a_1,...,a_{2^n-1}$$$ and $$$b_0,b_1,...,b_{2^n-1}$$$. The task is for each $$$i (0 leq i leq 2^n-1)$$$, to calculate $$$c_i=sum a_j cdot b_k$$$ ($$$jk=i$$$... | 3,200 | true | false | false | true | false | false | false | false | false | false | 5,524 |
710C | . Output Print _n_ lines with _n_ integers. All the integers should be different and from 1 to _n_2. The sum in each row, column and both main diagonals should be odd. | 1,500 | true | false | false | false | false | true | false | false | false | false | 6,980 |
1968C | You are given an array $$$x_2,x_3,dots,x_n$$$. Your task is to find any array $$$a_1,dots,a_n$$$, where: $$$1le a_ile 10^9$$$ for all $$$1le ile n$$$. $$$x_i=a_i bmod a_{i-1}$$$ for all $$$2le ile n$$$. Here $$$cbmod d$$$ denotes the remainder of the division of the integer $$$c$$$ by the integer $$$d$$$. For example... | 1,000 | false | false | false | false | false | true | false | false | false | false | 498 |
1806A | YunQian is standing on an infinite plane with the Cartesian coordinate system on it. In one move, she can move to the diagonally adjacent point on the top right or the adjacent point on the left. That is, if she is standing on point $$$(x,y)$$$, she can either move to point $$$(x+1,y+1)$$$ or point $$$(x-1,y)$$$. YunQi... | 800 | true | true | false | false | false | false | false | false | false | false | 1,442 |
932G | Problem - 932G - Codeforces =============== xa0 ]( --- Finished → 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 | true | false | false | false | false | false | false | 5,972 |
648D | Statement is not available on English language На координатной прямой сидит _n_ собачек, _i_-я собачка находится в точке _x__i_. Кроме того, на прямой есть _m_ мисок с едой, для каждой известна её координата на прямой _u__j_ и время _t__j_, через которое еда в миске остынет и станет невкусной. Это значит, что если соба... | 1,900 | false | true | false | false | true | false | false | false | true | false | 7,224 |
510D | Fox Ciel is playing a game. In this game there is an infinite long tape with cells indexed by integers (positive, negative and zero). At the beginning she is standing at the cell 0. There are also _n_ cards, each card has 2 attributes: length _l__i_ and cost _c__i_. If she pays _c__i_ dollars then she can apply _i_-th ... | 1,900 | true | false | false | true | false | false | true | false | false | false | 7,797 |
1253A | You're given two arrays $$$a[1 dots n]$$$ and $$$b[1 dots n]$$$, both of the same length $$$n$$$. In order to perform a push operation, you have to choose three integers $$$l, r, k$$$ satisfying $$$1 le l le r le n$$$ and $$$k > 0$$$. Then, you will add $$$k$$$ to elements $$$a_l, a_{l+1}, ldots, a_r$$$. For example, i... | 1,000 | false | false | true | false | false | false | false | false | false | false | 4,422 |
117E | You are given an undirected connected graph _G_ consisting of _n_ vertexes and _n_ edges. _G_ contains no self-loops or multiple edges. Let each edge has two states: on and off. Initially all edges are switched off. You are also given _m_ queries represented as (_v_,u2009_u_) — change the state of all edges on the shor... | 2,900 | false | false | true | false | true | false | false | false | false | false | 9,417 |
1227C | You are fed up with your messy room, so you decided to clean it up. Your room is a bracket sequence $$$s=s_{1}s_{2}dots s_{n}$$$ of length $$$n$$$. Each character of this string is either an opening bracket '(' or a closing bracket ')'. In one operation you can choose any consecutive substring of $$$s$$$ and reverse it... | 1,700 | false | false | false | false | false | true | false | false | false | false | 4,542 |
1862F | A portal of dark forces has opened at the border of worlds, and now the whole world is under a terrible threat. To close the portal and save the world, you need to defeat $$$n$$$ monsters that emerge from the portal one after another. Only the sorceress Vika can handle this. She possesses two magical powersxa0— water m... | 1,800 | false | false | false | true | false | false | true | true | false | false | 1,108 |
156B | As Sherlock Holmes was investigating a crime, he identified _n_ suspects. He knows for sure that exactly one of them committed the crime. To find out which one did it, the detective lines up the suspects and numbered them from 1 to _n_. After that, he asked each one: "Which one committed the crime?". Suspect number _i_... | 1,600 | false | false | true | false | true | true | false | false | false | false | 9,251 |
1265E | Creatnx has $$$n$$$ mirrors, numbered from $$$1$$$ to $$$n$$$. Every day, Creatnx asks exactly one mirror "Am I beautiful?". The $$$i$$$-th mirror will tell Creatnx that he is beautiful with probability $$$frac{p_i}{100}$$$ for all $$$1 le i le n$$$. Creatnx asks the mirrors one by one, starting from the $$$1$$$-st mir... | 2,100 | true | false | false | true | true | false | false | false | false | false | 4,372 |
1575H | The Winter holiday will be here soon. Mr. Chanek wants to decorate his house's wall with ornaments. The wall can be represented as a binary string $$$a$$$ of length $$$n$$$. His favorite nephew has another binary string $$$b$$$ of length $$$m$$$ ($$$m leq n$$$). Mr. Chanek's nephew loves the non-negative integer $$$k$$... | 2,200 | false | false | false | true | false | false | false | false | false | false | 2,761 |
1537A | An array $$$b$$$ of length $$$k$$$ is called good if its arithmetic mean is equal to $$$1$$$. More formally, if $$$$$$frac{b_1 + cdots + b_k}{k}=1.$$$$$$ Note that the value $$$frac{b_1+cdots+b_k}{k}$$$ is not rounded up or down. For example, the array $$$[1,1,1,2]$$$ has an arithmetic mean of $$$1.25$$$, which is not ... | 800 | true | true | false | false | false | false | false | false | false | false | 2,962 |
733E | The academic year has just begun, but lessons and olympiads have already occupied all the free time. It is not a surprise that today Olga fell asleep on the Literature. She had a dream in which she was on a stairs. The stairs consists of _n_ steps. The steps are numbered from bottom to top, it means that the lowest ste... | 2,400 | true | false | false | false | true | true | false | false | false | false | 6,860 |
1067D | Ivan plays some computer game. There are $$$n$$$ quests in the game. Each quest can be upgraded once, this increases the reward for its completion. Each quest has $$$3$$$ parameters $$$a_{i}$$$, $$$b_{i}$$$, $$$p_{i}$$$: reward for completing quest before upgrade, reward for completing quest after upgrade ($$$a_{i} < b... | 3,100 | true | true | false | true | false | false | false | false | false | false | 5,372 |
1493B | The time on the planet Lapituletti goes the same way it goes on Earth but a day lasts $$$h$$$ hours and each hour lasts $$$m$$$ minutes. The inhabitants of that planet use digital clocks similar to earth ones. Clocks display time in a format HH:MM (the number of hours in decimal is displayed first, then (after the colo... | 1,300 | false | false | true | false | false | false | true | false | false | false | 3,207 |
819A | Sometimes Mister B has free evenings when he doesn't know what to do. Fortunately, Mister B found a new game, where the player can play against aliens. All characters in this game are lowercase English letters. There are two players: Mister B and his competitor. Initially the players have a string _s_ consisting of the... | 2,200 | false | true | false | false | false | false | false | false | false | false | 6,480 |
1239F | I'm the Map, I'm the Map! I'm the MAP!!! Map In anticipation of new adventures Boots wanted to do a good deed. After discussion with the Map and Backpack, they decided to gift Dora a connected graph. After a long search, Boots chose $$$t$$$ graph's variants, which Dora might like. However fox Swiper wants to spoil his ... | 3,400 | false | false | true | false | false | false | false | false | false | true | 4,491 |
997E | A permutation $$$p$$$ of length $$$n$$$ is a sequence $$$p_1, p_2, ldots, p_n$$$ consisting of $$$n$$$ distinct integers, each of which from $$$1$$$ to $$$n$$$ ($$$1 leq p_i leq n$$$) . Let's call the subsegment $$$[l,r]$$$ of the permutation good if all numbers from the minimum on it to the maximum on this subsegment ... | 3,000 | false | false | false | false | true | false | false | false | false | false | 5,714 |
1793D | In winter, the inhabitants of the Moscow Zoo are very bored, in particular, it concerns gorillas. You decided to entertain them and brought a permutation $$$p$$$ of length $$$n$$$ to the zoo. A permutation of length $$$n$$$ is an array consisting of $$$n$$$ distinct integers from $$$1$$$ to $$$n$$$ in any order. For ex... | 1,800 | true | true | true | true | false | false | false | true | false | false | 1,517 |
1017G | Abendsen assigned a mission to Juliana. In this mission, Juliana has a rooted tree with $$$n$$$ vertices. Vertex number $$$1$$$ is the root of this tree. Each vertex can be either black or white. At first, all vertices are white. Juliana is asked to process $$$q$$$ queries. Each query is one of three types: 1. If verte... | 3,200 | false | false | false | false | true | false | false | false | false | false | 5,599 |
1717F | Oh no, on the first exam Madoka got this hard problem: Given integer $$$n$$$ and $$$m$$$ pairs of integers ($$$v_i, u_i$$$). Also there is an array $$$b_1, b_2, ldots, b_n$$$, initially filled with zeros. Then for each index $$$i$$$, where $$$1 leq i leq m$$$, perform either $$$b_{v_i} := b_{v_i} - 1$$$ and $$$b_{u_i} ... | 2,500 | false | false | true | false | false | true | false | false | false | true | 1,976 |
1268D | You are given a tournamentxa0— complete directed graph. In one operation you can pick any vertex $$$v$$$ and change the direction of all edges with $$$v$$$ on one of the ends (i.e all edges $$$u o v$$$ change their orientation to $$$v o u$$$ and vice versa). You want to make the tournament strongly connected with the... | 3,200 | true | false | false | false | false | false | true | false | false | true | 4,348 |
77C | Eat a beaver, save a tree!" — That will be the motto of ecologists' urgent meeting in Beaverley Hills. And the whole point is that the population of beavers on the Earth has reached incredible sizes! Each day their number increases in several times and they don't even realize how much their unhealthy obsession with tre... | 2,100 | false | true | false | true | false | false | false | false | false | false | 9,578 |
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