PinesL

A - Playing with Paper One day Vasya was sitting on a not so interesting Maths lesson and making an origami from a rectangular a mm  ×  b mm sheet of paper (a > b). Usually the first step in making...

D - Send a Table 题意：求1至n两个互质的数有级对，可交换顺序。题解：用欧拉函数求1至根号n内的，因为求1至n，所以结果*2，又因为1，1不算，所以结果要减一。#include <stdio.h> int getPhi(int n) { int phi = n; for(int i = 2; i * i <=...

I - 小兔的棋盘 小兔的叔叔从外面旅游回来给她带来了一个礼物，小兔高兴地跑回自己的房间，拆开一看是一个棋盘，小兔有所失望。不过没过几天发现了棋盘的好玩之处。从起点(0，0)走到终点(n,n)的最短路径数是C(2n,n),现在小兔又想如果不穿越对角线(但可接触对角线上的格点)，这样的路径数有多少?小兔想了很长时间都没想出来，现在想请你帮助小兔解决这个问题，...

C - Raising Modulo Numbers People are different. Some secretly read magazines full of interesting girls' pictures, others create an A-bomb in th...