A - Jzzhu and Sequences   Jzzhu has invented a kind of sequences, they meet the following property: You are given x and y, please calculate fn modulo 1000000007 (109 + 7). Input The first line contains two integers x and y (|x|, |y| ≤ 109). The secon…

E. Mahmoud and Ehab and the xor-MST dp/数学/找规律 题意 给出一个完全图的阶数n(1e18),点由0---n-1编号,边的权则为编号间的异或,问最小生成树是多少 思路 由于一个数k和比他小的数异或,一定可以取到k与所有正整数形成的异或值的最小值.这里简单得形式化证明一下 假设一个数为1000110 那么他的最佳异或和为010(即留下最靠近右边的1其他全部置0) 我们定义\(lsb(x)=x\And(-x)\)由字符形的变量编码我们可以知道,这就可以取得x最…

I was trying to solve problem '1234 - Harmonic Number', I wrote the following code long long H( int n ) {    long long res = 0;    for( int i = 1; i <= n; i++ )        res = res + n / i;    return res;} Yes, my error was that I was using the integer…

题目传送门 /* 数学/暴力:只要一个数的最后三位能被8整除,那么它就是答案:用到sprintf把数字转移成字符读入 */ #include <cstdio> #include <algorithm> #include <cstring> #include <iostream> #include <cmath> #include <vector> using namespace std; ; const int INF = 0x3f3…

Time Limit: 1000 MS In mathematics, the factorial of a positive integer number n is written as n! and is de ned as follows: n! = 1  2  3  4  : : :  (n  1)  n = ∏n i=1 i The value of 0! is considered as 1. n! grows very rapidly with the increase…

Triangle 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5914 Description 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 decides…

ural 2029 Towers of Hanoi Strike Back 链接:http://acm.timus.ru/problem.aspx?space=1&num=2029 题意:汉诺塔问题,给定一串只有(A, B, C)的字符串(A代表在第一根柱子,B代表在第二根柱子,C代表在第三根柱子),从前往后代表盘子的大小,第 i 个字母代表di i 个盘子在某个柱子上.问移动给定字母状态的盘子最少需要多少步. 思路:首先,从后往前看(最大的盘子),如果不在当前柱子上,那么移动到目标柱子需要 2…

传送门: http://acm.hdu.edu.cn/showproblem.php?pid=1273 漫步森林 Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3508    Accepted Submission(s): 2339 Problem Description Gardon和小希每天晚上都喜欢到屋外的森林里散步,设森林里有N…

观察一下序列,每3个数一组,第一个数余1,不能,加第二个数后整除(第二个数本身余2),第三数恰整除.一行代码的事.011011011.... #include<iostream> using namespace std; int main() { int n; while(cin>>n) { cout<<n/3*2+(n%3==2?1:0)<<endl; } return 0; }…

Detachment Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1686    Accepted Submission(s): 467 Problem Description In a highly developed alien society, the habitats are almost infinite dimension…