Content 有 \(n\) 个数 \(a_1,a_2,a_3,...,a_n\).试求出使得 \(a_i\) 与其他所有整数的算术平均值相等的所有 \(i\). 数据范围:\(2\leqslant n\leqslant 2\times10^5,1\leqslant a_i\leqslant 1000\). Solution 我们可以将其转化为:求出能满足 \(a_i=\dfrac{\sum\limits_{j=1}^na_j-a_i}{n-1}\) 的所有 \(i\).直接在数列中扫一遍看能…

题目 Volodya is an odd boy and his taste is strange as well. It seems to him that a positive integer number is beautiful if and only if it is divisible by each of its nonzero digits. We will not argue with this and just count the quantity of beautiful…

Problem Description Fermat's theorem states that for any prime number p and for any integer a > 1, a^p == a (mod p). That is, if we raise a to the pth power and divide by p, the remainder is a. Some (but not very many) non-prime values of p, known as…

Problem Description A number whose only prime factors are 2,3,5 or 7 is called a humble number. The sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 24, 25, 27, ... shows the first 20 humble numbers. Write a program to find and pri…

Add Two Numbers: You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You may assum…

Raising Modulo Numbers Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 6347   Accepted: 3740 Description People are different. Some secretly read magazines full of interesting girls' pictures, others create an A-bomb in their cellar, oth…

Content 给定一个 \(1\sim n\) 的排列,请求出对于 \(1\leqslant m\leqslant n\),是否存在一个区间满足这个区间是一个 \(1\sim m\) 的排列. 数据范围:\(1\leqslant n,\sum n\leqslant 2\times 10^5\). Solution 看到本题的唯一一篇主席树+二分的题解里面并没有说最巧妙的方法是什么,那我就来给大家讲讲吧qwq. 对于每一个 \(m\),我们不妨弄个双指针 \(l,r\),然后从 \(1\) 的位…

原题地址 题目大意:有一个函数\(f(x)\),效果是将\(x+1\)后,去掉末尾所有的\(0\),例如: \(f(599)=6\),因为\(599+1=600→60→6\) \(f(7)=8\),因为\(7+1=8\) \(f(9)=1\),因为\(9+1=10→1\) \(f(10099)=101\),因为\(10099+1=10100→1010→101\) 我们可以多次进行函数\(f(x)\)的运算,从而让一个数\(x\)转换为另一个数,例如\(10098\)可以转换为\(102\),因为…

https://vjudge.net/problem/CodeForces-359D http://codeforces.com/problemset/problem/359/D 题目大意: 给一串数,问一个区间内所有的数是否能被其其中一个数所全部整除,求出满足条件的区间的长度最大值,并输出这样的区间的个数与它们的左端点. 换句话将,求区间GCD=区间MIN的最大长度区间. 明显st表解决. 对于最大区间长度,二分判断即可. (因为在poj做过类似的题所以思路能很快……就是题看不懂有点难,所以特…

把电话号码转换成为词典中能够记忆的的单词的组合,找到最短的组合. 我这道题应用到的知识点: 1 Trie数据结构 2 map的应用 3 动态规划法Word Break的知识 4 递归剪枝法 思路: 1 建立Trie字典树.方便查找, 可是字典树不是使用字符来建立的.而是把字符转换成数字.建立一个数字字典树. 然后叶子节点设置一个容器vector<string>装原单词. 2 动态规划建立一个表,记录能够在字典树中找到的字符串的前缀子串 3 假设找到整个串都在字典树中,那么就能够直接返回这个单词…