Add English statements

final/bitryssland/problem_statement/problem.en.tex

@@ -0,0 +1,44 @@
+\problemname{Bitrussia}
+\illustration{0.3}{coins.jpg}{Picture by \href{https://commons.wikimedia.org/wiki/File:Assorted_United_States_coins.jpg}{Elembis} (public domain)}
+In the Republic of Bitrussia, a new coin system has recently been introduced.
+There are $N$ different coin denominations worth $2^0, 2^1, 2^2, ..., 2^{N-1}$.
+
+The small town of Napsaks is known for being full of interesting shops.
+At the same time, Napsaks is notorious for never having any change in the shops.
+You are also not allowed to pay more than the price.
+It is therefore very important to bring plenty of coins of suitable denominations to be able to buy everything you want.
+
+In Napsaks lives Darja-Pavla.
+She is planning to go Christmas shopping and has brought $a_i$ coins of value $2^i$ ($i = 0, 1, ..., N-1$).
+She will visit $M$ different shops and buy one thing in each shop.
+The item she buys in shop $i$ costs $b_i$ ($i = 0, 1, ..., M-1$).
+She is of course worried that her coins will not be enough to pay for everything she wants to buy. Help her determine this!
+
+\section*{Input}
+The first line contains two integers $1 \le N \le 50$ and $1 \le M \le 100\,000$, separated by spaces.
+The next line contains the $N$ space-separated integers $0 \le a_0, a_1, ..., a_{N-1} \le 10^{15}$.
+The third and last line contains the $M$ space-separated integers $0 \le b_0, b_1, ..., b_{M-1} \le 10^{15}$.
+
+\section*{Output}
+Output \texttt{ja} if Darja-Pavla can pay for everything she wants to buy with her coins.
+Otherwise, output \texttt{nej}.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l |}
+\hline
+Group & Points & Constraints \\ \hline
+1     & 19         & $M = 1, a_i \le 1$ \\ \hline
+2     & 46         & $M = 1$ \\ \hline
+3     & 35         & No additional constraints. \\ \hline
+\end{tabular}
+
+\section*{Explanation of Sample 1}
+In the sample, Darja-Pavla has one coin worth $1$, three coins worth $2$, and one coin worth $4$.
+She can pay for the item costing $5$ by using one coin worth $1$ and one coin worth $4$ ($1 + 4 = 5$).
+She can then pay for the item costing $6$ with the three remaining coins of value $2$ ($2 + 2 + 2 = 6$).
+
+\section*{Explanation of Sample 2}
+In the sample, both items require that a coin of denomination $1$ is used, but she only has one coin of this denomination.

final/julklappskop/problem_statement/problem.en.tex

@@ -0,0 +1,37 @@
+\problemname{Christmas Shopping}
+\illustration{0.3}{christmastree.jpg}{Picture by \href{https://commons.wikimedia.org/wiki/File:Christmas_presents_and_a_tree.jpg}{Trogain} (cc-by-sa4.0)}
+Kind Allnäs is going to buy \emph{one Christmas present each} for her $K$ friends (even though it is February --- Allnäs believes in having a good margin).
+The store she is in has \emph{exactly one} copy of each item.
+There are $N$ items in total.
+Allnäs knows her friends very well --- she knows exactly who likes what and how much.
+She has written down a list of all $a_{ij}$ values, the numbers describing how much friend $i$ likes present $j$.
+
+Now Allnäs wants to maximize her friends' happiness.
+She wants to give her friends presents in such a way that the sum of happiness for each friend (i.e.\ the values $a_{ij}$) is maximized.
+Which Christmas presents should she buy to maximize the sum of her friends' happiness?
+
+\section*{Input}
+The first line contains two integers $K$ (number of friends) and $N$ (number of presents).
+
+The following $K$ lines contain $N$ integers each.
+On the $i$th line, the $j$th integer is $0 \le a_{ij} \le 10^8$ --- how happy the $i$th friend becomes if they receive the $j$th present.
+
+\section*{Output}
+You shall output one integer --- the maximum sum of the friends' happiness.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l | l |}
+\hline
+Group & Points & Constraints \\ \hline
+1     & 8          & $K = 2, 1 \le N \le 5000$ \\ \hline
+2     & 15         & $K = 2, 1 \le N \le 100\,000$ \\ \hline
+3     & 30         & $1 \le K \le 8, 1 \le N \le 100\,000$ \\ \hline
+4     & 27         & $1 \le K \le 14, 1 \le N \le 200$ \\ \hline
+5     & 20         & $1 \le K \le 14, 1 \le N \le 100\,000$ \\ \hline
+\end{tabular}
+
+\section*{Explanation of Sample 1}
+If Allnäs buys present 3 for friend 1 and present 2 for friend 2, the sum is $a_{31} + a_{22} = 4 + 7 = 11$, which is the best possible.

final/kubiskaboxar/problem_statement/problem.en.tex

@@ -0,0 +1,57 @@
+\problemname{Cubic Boxes}
+Your second cousin Paulo R loves boxes.
+Right now you are on your way to celebrate Christmas with Paulo (traditionally you celebrate Christmas once with each part of your family, which currently consists of 72 different families).
+Unfortunately, you have just realized that you forgot to buy Christmas presents!
+
+Since Paulo loves boxes, that is exactly what you plan to buy for him.
+A box is cubic with a certain side length, and has one of three colors --- red (R), green (G), or blue (B).
+You have written a shopping list with all the boxes you plan to buy.
+Unfortunately, the boxes are sold in three different stores, where each store sells boxes of a certain color.
+
+Your plan is now to visit all three stores to buy the necessary boxes.
+To save space in the luggage compartment, you plan to place some of the boxes inside each other.
+If you visit the stores in the order $f_1, f_2, f_3$ (e.g.\ R, G, B), you may place boxes of color $f_3$ inside boxes of color $f_2$, and boxes of color $f_2$ inside boxes of color $f_1$.
+The order R, G, B thus means you can place blue boxes inside green boxes, and green boxes inside red boxes.
+You may \textbf{not} place boxes of color $f_3$ inside boxes of color $f_1$ --- that would be completely absurd.
+Furthermore, a box can only be placed inside a box with a \textbf{strictly larger} side length.
+
+\begin{figure}[h!]
+  \centering
+  \includegraphics[width=0.5\textwidth]{sample3}
+  \caption{A possible solution to sample 3.
+  On the left, a green box is placed inside a red box which is placed inside a blue box.
+  On the right, a green box is placed inside a red box.}
+  \label{fig:sample3}
+\end{figure}
+
+Can you determine in what order to visit the stores to minimize the number of \emph{outer boxes} (i.e.\ boxes that are not inside another box), if you place the boxes optimally?
+
+\section*{Input}
+The input starts with the number $N$, the number of boxes, where $1\le N \le 1\,000$. Then follow $N$ lines with side length
+$l_i$ ($1 \le l_i \le 10\,000\,000$) and color $f_i$ (R, G, or B) for each box.
+
+\section*{Output}
+You shall output two lines.
+The first line shall contain the order you visit the stores in, in the form $f_1\text{ }f_2\text{ }f_3$.
+The second line shall consist of one integer --- the minimum number of outer boxes you can achieve after placing boxes inside each other.
+
+If multiple orders give the same minimum number of outer boxes, you may output any of these orders.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l |}
+\hline
+Group & Points & Constraints \\ \hline
+1     & 50         & You will always visit the stores in the order \texttt{B G R} \\ \hline
+2     & 50         & No additional constraints. \\ \hline
+\end{tabular}
+
+\section*{Explanation of Sample 3}
+A possible solution is illustrated in Figure~\ref{fig:sample3}.
+The optimal order is to visit the stores in the order blue, red, green.
+
+We can then place the two G boxes (size 1) inside one R box (size 10) each.
+After that, one of the R boxes can be placed inside a B box.
+This leaves one R box and one B box as outer boxes.

final/snobollskrig1/problem_statement/problem.en.tex

@@ -0,0 +1,62 @@
+\problemname{Snowball Fight 1}
+\illustration{0.3}{snowballs.jpg}{Picture by \href{https://commons.wikimedia.org/wiki/File:Large_snowball_fight_near_Khaju_bridge.jpg}{Manfy} (cc-by-sa3.0)}
+In an \href{https://en.wikipedia.org/wiki/Graph_(discrete_mathematics)}{undirected, weighted graph}
+with $N$ nodes, $L$ countries are having a snowball fight during IOI.
+In the beginning, each country has a fort at some node.
+
+At time $0$, each country starts heading out for the snowball fight. The snowball fight works as follows:
+
+\begin{itemize}
+\item If a country owns a fort, the contestants from that country head out along all edges from the fort, all at the same speed.
+\item If two countries meet along an edge, the countries stop and fight (forever).
+\item If two countries meet at a node, the countries stop and fight (forever).
+\item If a country reaches a node where countries are already fighting, it joins the fight.
+\item If a country reaches a node before any other country, that country builds a fort at the node, and then heads out along the edges from the node according to rule 1.
+\end{itemize}
+
+Note that the rules imply that at most one country can have a fort at a given node.
+If two countries arrive at a node at the same time, the contestants who arrived at the node will stay there and fight forever, without heading further.
+
+Determine which pairs of countries will fight each other.
+
+\section*{Input}
+
+The first line contains three integers $N,L,M$ ($2 \le N \le 100\,000, 2 \le L \le 50, 1 \le M \le 100\,000$):
+the number of nodes, countries, and edges in the graph, respectively.
+Then follow $L$ lines with integers, specifying which node each country's starting base is at.
+Finally follow $M$ lines with three integers each $a, b, w$ ($0 \le a,b < N, a \neq b, 1 \le w \le 2\,000$).
+This means there is an (undirected) edge between nodes $a$ and $b$ (zero-indexed), of length $w$.
+
+There will be at most one edge between each pair of nodes, and no two countries will start at the same node.
+
+\section*{Output}
+
+For each pair of countries $a, b$ that fight, output a line \texttt{a b}, where $a < b$ and the countries are indexed from 0.
+These shall be output in sorted order, sorted by the first index first.
+If for example $L = 3$ and all three countries fight, you shall output:
+\begin{lstlisting}
+0 1
+0 2
+1 2
+\end{lstlisting}
+
+\section*{Explanation of Sample 1}
+
+In this example, the graph is a cycle and almost entirely symmetric. In the case between
+country 0 and country 3, the fight will take place on an edge, while the other 3 fights
+will take place at nodes.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l |}
+\hline
+Group & Points & Constraints \\ \hline
+1     & 8          & The graph is a line: the edges are exactly (0,1), (1,2), etc., (N-2, N-1) \\ \hline
+2     & 9          & $L = 2$. \\ \hline
+3     & 24         & $w = 1$ for all edges. \\ \hline
+4     & 23         & No fights occur at nodes. \\ \hline
+5     & 29         & $1 \le N, M \le 2\,000$. \\ \hline
+6     & 7          & No additional constraints. \\ \hline
+\end{tabular}

final/snomurskontrollant/problem_statement/problem.en.tex

@@ -0,0 +1,56 @@
+\problemname{Snow Wall Inspector}
+The PO jury cannot program. After the fiasco in the online qualification, where the broken judge for the problem \href{https://pokval16.kattis.com/problems/pokval16.snomur}{Snow Wall} accidentally gave Iceland the win with 211.58 out of 100 points on the problem, the jury has decided to outsource its judges to people who can actually code --- PO finalists.
+
+The problem was as follows:
+
+Sweden is building a snow wall of a certain width $W$.
+As building material, there are a number of snow blocks that all have height 1, but can have different widths.
+When the wall is constructed, each block must satisfy the following rule: on the row below the block,
+at the two positions where the block has its endpoints, there must be a block immediately to the right and left of the point,
+except at the beginning and end of a row, where there must instead be an endpoint \emph{on every row} (see the left, second-from-top wall in Figure~\ref{fig:sample} where this is missing on the top row).
+
+Furthermore, there must not be a gap at the same position on two directly consecutive rows \emph{in the wall} (the empty row
+just above the wall does not count).
+
+The following image illustrates some invalid (left) and valid (right) walls:
+
+\begin{figure}[h]
+	\centering
+	\includegraphics[width=0.7\textwidth]{mur.png}
+	\caption{A number of invalid (left) and valid (right) walls.}
+  \label{fig:sample}
+\end{figure}
+
+Given a proposal for how the wall should look, determine whether the wall is a valid wall.
+
+\section*{Input}
+The first line contains two integers $W$ and $H$ --- the width and height of the wall.
+
+The following $H$ lines describe the rows of the wall.
+Each line starts with an integer $B \ge 1$, the number of blocks on the row.
+This is followed by $B$ pairs of integers $P_j, L_j$, the (zero-indexed) position and length of the $j$th block on the row. These will be given in increasing $P_j$ order, i.e.\ from left to right.
+No blocks will overlap or extend outside the wall.
+
+The rows are given from the bottom up --- i.e.\ the first row in the input is the bottom row of the wall.
+
+Let the sum of the number of blocks over all rows be $N$.
+This value has limits in the scoring table.
+
+\section*{Output}
+You shall output \texttt{YES} if the wall is valid, and \texttt{NO} if it is not.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l | l |}
+\hline
+Group & Points & Constraints & Other \\ \hline
+1     & 31         & $1 \le N, W, H \le 100\,000$ & No gap occurs directly above another gap \\ \hline
+2     & 34         & $1 \le N, W, H \le 1\,000$ & \\ \hline
+3     & 35         & $1 \le N, W, H \le 100\,000$ & \\ \hline
+\end{tabular}
+
+\section*{Explanation of Samples}
+The first four samples correspond to the four invalid walls on the left in the image.
+The last four samples correspond to the four valid walls on the right in the image.

katt/brobygge/problem_statement/problem.en.tex

@@ -0,0 +1,41 @@
+\def\version{1}
+\problemname{Bridge Building}
+In the island nation of Graf Kantaria, there are $N$ islands connected by $N - 1$ bridges, in such a way that it is possible to travel between every pair of islands using these bridges.
+
+President Vick T. Adgraf and her husband Rick T. Adgraf have realized there are problems with this infrastructure setup.
+The bridges were built because it was cheap, not because it would be fast to travel between the islands.
+To increase their approval ratings, Vick and Rick want to build one extra bridge each in the nation.
+They have written down some proposals for new bridges to build, and want to compare how the extra bridges change the distances between certain pairs of islands.
+
+Your task is to write a program that, given all current bridges in the island nation and a list of either zero, one, or two extra bridges, can answer what the shortest distance between two islands becomes if the extra bridges are built.
+
+\section*{Input}
+The first line contains the integer $2 \le N \le 10^5$.
+Then follow $N - 1$ lines, one for each of the current bridges.
+The $i$th line contains the integers $0 \le A[i] \not= B[i] < N$ and $1 \le L[i] \le 1000$.
+$A[i]$ and $B[i]$ give the islands that are the endpoints of the $i$th bridge, which has length $L[i]$.
+
+The next line contains the integer $0 \le E \le 2$, the number of extra bridges your program should take into account.
+The following $E$ lines contain the description of a bridge, in the same format as the original bridges.
+None of the extra bridges coincide with the original bridges, or with each other.
+
+The next line contains $0 \le Q \le 10^5$, the number of pairs of islands you need to find the shortest distance between.
+Then follow $Q$ lines.
+The $i$th of these contains the two distinct integers $F[i]$ and $T[i]$.
+
+\section*{Output}
+You shall output $Q$ lines.
+The $i$th of these shall contain the shortest distance between islands $F[i]$ and $T[i]$.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l |}
+\hline
+Group & Points & Constraints \\ \hline
+	1     & 25         & The original bridges connect islands 0 and 1, 1 and 2, $\dots$, $n - 2$ and $n - 1$\\ \hline
+	2     & 25         & $E = 0$ \\ \hline
+	3     & 25         & $E = 1$ \\ \hline
+	4     & 25         & $E = 2$ \\ \hline
+\end{tabular}

katt/hemkor/problem_statement/problem.en.tex

@@ -0,0 +1,50 @@
+\def\version{1}
+\problemname{Home Delivery}
+Carl has just moved away from home, and has realized that he now needs to buy food himself.
+Since it is tiresome to go to the store, he instead orders the food online from the website \emph{Hemkör}, which delivers groceries directly to his door.
+
+Carl is now buying food for the coming centuries.
+In total, Carl has planned to eat $1 \le N \le 5\,000$ meals (numbered from $1$ to $N$) during the next $100\,000$ days.
+Carl plans to eat the $i$th meal $1 \le P[i] \le 100\,000$ days from today, and it requires a total of $1 \le Q[i] \le 100$ kilograms of food.
+Carl is not picky --- as long as he has $Q[i]$ kilograms of ingredients, it does not matter which ingredients he uses.
+
+On Hemkör, there are $1 \le M \le 100\,000$ different grocery items for sale.
+The $i$th item has a weight of $1 \le V[i] \le 100$ kilograms, a cost of $1 \le K[i] \le 2\,000$ kronor, and an expiration date that is $1 \le D[i] \le 100\,000$ days from today (an item can be used up \emph{to and including} the day it expires).
+Carl can buy as many copies of each grocery item as he wants.
+
+Carl has determined that it is possible to buy groceries so that he can prepare all meals.
+Can you help him order groceries in a way that is also as cheap as possible?
+
+\section*{Example}
+Suppose Carl plans to prepare $2$ meals on days $1$ and $10$, with weights $4$ kilograms and $1$ kilogram.
+There are three grocery items, with weights $4$, $2$, and $4$ kilograms, costs $10$, $2$, and $3$, and expiration dates $10$, $5$, $5$.
+Carl can buy one copy of the first item and one copy of the second item.
+For the first meal, he can use $2$ kilograms of each item.
+For the second meal, he uses $1$ kilogram of the first item, which expires on the same day the meal is prepared.
+One kilogram of the first item is left over and not used.
+
+In total, this costs $10 + 2 = 12$ kronor.
+
+\section*{Input}
+The first line contains the positive integers $N$ and $M$.
+Then follow $N$ lines, one for each meal.
+The $i$th line contains the integers $P[i]$ and $Q[i]$.
+
+Then follow $M$ lines, one for each item.
+The $i$th line contains the integers $V[i]$, $K[i]$, and $D[i]$.
+
+\section*{Output}
+Output one number --- the minimum cost to buy food for all meals.
+
+\section*{Scoring}
+Your solution will be tested on a set of test groups. To earn points for a group, you must pass all test cases in that group.
+
+\noindent
+\begin{tabular}{| l | l | l |}
+\hline
+  Group & Points & Constraints \\ \hline
+  1     & 31         & $N \le 100, M \le 100$ \\ \hline
+  2     & 19         & $P[i] = 1$ for all meals \\ \hline
+  3     & 15         & $V[i] = 1$ for all items \\ \hline
+  4     & 35         & No additional constraints. \\ \hline
+\end{tabular}