TJICSHAN的博客

   A - Stages Natasha is going to fly to Mars. She needs to build a rocket, which consists of several stages in some order. Each of the stages is defined by a lowercase Latin letter. This way, the r...

B - Triangle  HDU - 5914  Mr. Frog has n sticks, whose lengths are 1,2, 3⋯⋯n respectively. Wallice is a bad man, so he does not want Mr. Frog to form a triangle with three of the sticks here. He dec...