题目描述You are given four integers: $H, W, h$ and $w$. Determine whether there exists a matrix such that all of the following conditions are held, and construct one such matrix if the answer is positive:

题目描述Memory and his friend Lexa are competing to get higher score in one popular computer game. Memory starts with score $a$ and Lexa starts with score $b$. In a single turn, both Memory and Lexa get s

题目描述Snuke can change a string $t$ of length $N$ into a string $t’$ of length $N-1$ under the following rule: for each $i \ (1 \le i \le N-1)$, the $i$-th character of $t’$ must be either the $i$-th o

题目描述There are $N$ cats. We number them from $1$ through $N$. Each of the cats wears a hat. Cat $i$ says: “there are exactly $a_i$ different colors among the $N-1$ hats worn by the cats except me.” Det

题目描述You are given an array $a$ consisting of $n$ elements. The imbalance value of some subsegment of this array is the difference between the maximum and minimum element from this segment. The imbalan

题目描述Ivan likes to learn different things about numbers, but he is especially interested in really big numbers. Ivan thinks that a positive integer number $x$ is really big if the difference between $x

题目描述There are $n$ boxes with colored balls on the table. Colors are numbered from $1$ to $n$. $i$-th box contains $a_i$ balls, all of which have color $i$. You have to write a program that will divide

题目描述There is a pile of $N$ books on the table. Two types of operations are performed over this pile: a book is added to the top of the pile, top $K$ books are rotated. If there are less than $K$ book

题目描述A new web-design studio, called SMART (Simply Masters of ART), employs two people. The first one is a web-designer and an executive director at the same time. The second one is a programmer. The d