灰鲭鲨

摘要： Problem StatementThere are integers with $N$ different values written on a blackboard. The $i$-th value is $A_i$ and is written $B_i$ times. You may r 阅读全文

摘要： Problem Statement$2^N$ people, numbered $1$ to $2^N$, will participate in a rock-paper-scissors tournament. The tournament proceeds as follows: The pa 阅读全文

摘要： Problem StatementA sport event is held in June of every year whose remainder when divided by $4$ is $2$. Suppose that it is now January of the year $Y 阅读全文

摘要： Problem StatementThere is an empty sequence $X$ and an empty stack $S$. Also, you are given an integer sequence $A=(a_1,\ldots,a_N)$ of length $N$. Fo 阅读全文

摘要： Problem StatementYou are given a simple undirected graph with $N$ vertices and $M$ edges. The vertices are numbered $1, \dots, N$, and the $i$-th $(1 阅读全文

摘要： Problem StatementYou are given a sequence $a = (a_1, \dots, a_N)$ of length $N$ consisting of integers between $1$ and $N$. Find the number of pairs o 阅读全文

摘要： Problem StatementYou are given a sequence of positive integers $A=(a_1,\ldots,a_N)$ of length $N$. There are $(2^N-1)$ ways to choose one or more term 阅读全文

摘要： Problem StatementYou are given a simple undirected graph with $N$ vertices and $M$ edges. The vertices are numbered $1, \dots, N$, and the $i$-th $(1 阅读全文

摘要： Problem StatementYou are given a sequence $P = (p_1,p_2,\ldots,p_N)$ that contains $1,2,\ldots,N$ exactly once each. You may perform the following ope 阅读全文

摘要： Problem StatementWe have a number line. Takahashi painted some parts of this line, as follows: First, he painted the part from $X=L_1$ to $X=R_1$ red. 阅读全文