摘要： DescriptionGiven a rectangle and a circle in the coordinate system(two edges of the rectangle are parallel with the X-axis, and the other two are para... 阅读全文

摘要： DescriptionThere is a hill with n holes around. The holes are signed from 0 to n-1.A rabbit must hide in one of the holes. A wolf searches the rabbit ... 阅读全文

摘要： DescriptionIgnatius is doing his homework now. The teacher gives him some articles and asks him to tell how many times each letter appears.It's really... 阅读全文

摘要： Description两只青蛙在网上相识了，它们聊得很开心，于是觉得很有必要见一面。它们很高兴地发现它们住在同一条纬度线上，于是它们约定各自朝西跳，直到碰面为止。可是它们出发之前忘记了一件很重要的事情，既没有问清楚对方的特征，也没有约定见面的具体位置。不过青蛙们都是很乐观的，它们觉得只要一直朝着某个... 阅读全文

摘要： 欧拉函数是积性函数——若m,n互质，φ(mn)=φ(m)φ(n)。特殊性质：当n为奇数时，φ(2n)=φ(n),φ(x)=x(1-1/p1)(1-1/p2)(1-1/p3)(1-1/p4)…..(1-1/pn),其中p1,p2,p3,p4,……pn为x的所有质因数，原因：如果x = p^k,那么p的... 阅读全文

摘要： 逐渐发现找规律的美妙之处啦，真不错，用普通方法解决很久或者很麻烦的问题，找到规律就很方便，算法最主要还是思想DescriptionThere are another kind of Fibonacci numbers: F(0) = 7, F(1) = 11, F(n) = F(n-1) + F(n... 阅读全文

摘要： DescriptionMatt’s friend K.Bro is an ACMer.Yesterday, K.Bro learnt an algorithm: Bubble sort. Bubble sort will compare each pair of adjacent items and... 阅读全文

摘要： #include using namespace std;class num{public: num(){n = 1;} ~num(){} int get()const{return n;} void set(int i){n = i;} void operator++... 阅读全文

摘要： 网上搜了，好多c++里的东西啊有思路不会做，真烦，还是好好学c++；先把题和代码粘过来，过几天学c++好了再看http://acm.hust.edu.cn/vjudge/contest/view.action?cid=94494#problem/C#include #include #include... 阅读全文

摘要： DescriptionA tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edg... 阅读全文