Problem Description Tomorrow is contest day, Are you all ready? We have been training for 45 day

Problem Description Goldbach’s Conjecture: For any even number n greater than or equal to 4, there exists at least one pair of prime numbers p1 and p2 such th...

Problem Description Give a number n, find the minimum x(x>0) that satisfies 2^x mod n = 1.

Problem Description A weird clock marked from 0 to 59 has only a minute hand. It won’t move until a special coin is thrown into its box. There are different k...

Problem Description Starting from point (0,0) on a plane, we have written all non-negative integers 0, 1, 2,… as shown in the figure. For example, 1, 2, and 3...

Problem Description Given a positive integer n and the odd integer o and the nonnegative integer p such that n = o2^p.

Problem Description As part of an arithmetic competency program, your students will be given randomly generated lists of from 2 to 15 unique positive integers...

Problem Description 一个正整数，如果从左向右读（称之为正序数）和从右向左读（称之为倒序数）是一样的，这样的数就叫回文数。任取一个正整数，如果不是回文数，将该数与他的倒序数相加，若其和不是回文数，则重复上述步骤，一直到获得...

Problem Description 数论中有许多猜想尚未解决，其中有一个被称为“角谷猜想”的问题，该问题在五、六十年代的美国多个著名高校中曾风行一时，这个问题是这样描述的：任何一个大于一的自然数，如果是奇数，则乘以三再加一；如果...

Problem Description Welcome to 2006’4 computer college programming contest!