青铜时代

Given four numbers, can you get twenty-four through the addition, subtraction, multiplication, and division? Each number can be used only once. Input The input consists of multiple test cases. Each t

Given a set of sticks of various lengths, is it possible to join them end-to-end to form a square? Input The first line of input contains N, the number of test cases. Each test case begins with an i

小Hi和小Ho准备国庆期间去A国旅游。A国的城际交通比较有特色：它共有n座城市(编号1-n)；城市之间恰好有n-1条公路相连，形成一个树形公路网。小Hi计划从A国首都(1号城市)出发，自驾遍历所有城市，并且经过每一条公路恰好两次——来回各一次——这样公路两旁的景色都不会错过。 令小Hi苦恼的是他的小伙伴小Ho希望能以某种特定的顺序游历其中m个城市。例如按3-2-5的顺序游历这3座城市。(具体来