Smith Numbers Background While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University , noticed that the telephone number of his brother-in-law H. Smith had the following peculiar property: The sum of the digits o…

  Carmichael Numbers  An important topic nowadays in computer science is cryptography. Some people even think that cryptography is the only important field in computer science, and that life would not matter at all without cryptography. Alvaro is one…

题目链接:uva 12050 - Palindrome Numbers 题意:求第n个回文串 思路:首先可以知道的是长度为k的回文串个数有9*10^(k-1),那么依次计算,得出n是长度为多少的串,然后就得到是长度为多少的第几个的回文串了,有个细节注意的是, n计算完后要-1! 下面给出AC代码: #include <bits/stdc++.h> typedef long long ll; using namespace std; ; ll num[maxn]; int n,ans[maxn]…

Description 题目描述 While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University, noticed that the telephone number of his brother-in-law H. Smith had the following peculiar property: The sum of the digits of that nu…

UVa 10006 - Carmichael Numbers An important topic nowadays in computer science is cryptography. Some people even think that cryptography is the only important field in computer science, and that life would not matter at all without cryptography. Alvar…

欢迎访问我的新博客:http://www.milkcu.com/blog/ 原文地址:http://www.milkcu.com/blog/archives/uva10042.html 原创:Smith Numbers - PC110706 作者:MilkCu 题目描述 Smith Numbers   While skimming his phone directory in 1982, mathematician Albert Wilansky noticed that the telepho…

Description While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University,noticed that the telephone number of his brother-in-law H. Smith had the following peculiar property: The sum of the digits of that number w…

题意:给定一个N,求一个大于N的最小的Smith Numbers,Smith Numbers是一个合数,且分解质因数之后上质因子每一位上的数字之和 等于 其本身每一位数字之和(别的博客偷的题意) 思路:主要是分治:分解成质因子使用递归即可. #include<cstdio> #include<cmath> // 检测素数 bool is_prime(int n) { ; i*i <= n;++i) ){ ; } ; } //数位 int sumfun(int n) { ; ;…

                               Smith Numbers Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 14521   Accepted: 4906 Description While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University,noticed tha…

UVA.136 Ugly Numbers (优先队列) 题意分析 如果一个数字是2,3,5的倍数,那么他就叫做丑数,规定1也是丑数,现在求解第1500个丑数是多少. 既然某数字2,3,5倍均是丑数,且1为丑数,那么不妨从1开始算起.算完之后2,3,5均为丑数,然后再从2算起,4,5,10均为丑数--直到算到第1500个即可.那么有如下的问题: 如何从算出来的丑数中取出最小的? 如何保证没有计算重复的丑数? 对于第一个问题,可以采用优先队列的方法,即有序的队列,且为升序,每次只需要取出队首元素即可…