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There are n planets in the planetary system of star X. They orbit star X in circular orbits located in the same plane. Their tangent velocities are constant. Directions of orbiting of all planets are t

Given two positive integers G and L, could you tell me how many solutions of (x, y, z) there are, satisfying that gcd(x, y, z) = G and lcm(x, y, z) = L? Note, gcd(x, y, z) means the greatest common d

Given you a sequence of number a 1, a 2, …, a n, which is a permutation of 1…n. You need to answer some queries, each with the following format: Give you two numbers L, R, you should calculate sum

n pagodas were standing erect in Hong Jue Si between the Niushou Mountain and the Yuntai Mountain, labelled from 1 to n. However, only two of them (labelled a and b, where 1≤a≠b≤n) withstood the test ...