题目链接:http://acm.bnu.edu.cn/bnuoj/problem_show.php?pid=34985 题目大意:问n长度的串用0~k的数字去填,有多少个串保证任意子串中不包含0~k的某一个全排列 邀请赛上A的较多的一道题,比赛的时候死活想不出,回来之后突然就想通了,简直..... = =! 解题思路: 对于所有串我们都只考虑末尾最多有多少位能构成全排列的一部分(用l来表示),即最多有多少位不重复的数字出现,将问题转化为求末尾最多有k位能构成全排列的串的总数量 假设k为5,有一个…

题目链接:http://acm.bnu.edu.cn/bnuoj/problem_show.php?pid=34985 We define a kind of strings as elegant string: among all the substrings of an elegant string, none of them is a permutation of "0, 1,…, k". Let function(n, k) be the number of elegant s…

http://www.bnuoj.com/bnuoj/problem_show.php?pid=16493 [题解]:矩阵快速幂 [code]: #include <cstdlib> #include <cstring> #include <cstdio> #include <iostream> using namespace std; int N; struct matrix { ][]; }origin,res; matrix multiply(matr…

题目 题目描述 JSZKC is going to spend his vacation! His vacation has N days. Each day, he can choose a T-shirt to wear. Obviously, he doesn’t want to wear a singer color T-shirt since others will consider he has worn one T-shirt all the time. To avoid this…

[解题思路] 给一张神图,推理写的灰常明白了,关键是构造共轭函数,这一点实在是要有数学知识的理论基础,推出了递推式,接下来就是矩阵的快速幂了. 神图: 给个大神的链接:构造类斐波那契数列的矩阵快速幂 /* * Problem: HDU No.4565 * Running time: 62MS * Complier: G++ * Author: javaherongwei * Create Time: 9:55 2015/9/21 星期一 */ #include <bits/stdc++.h>…

hihocoder 1084 : http://hihocoder.com/problemset/problem/1084 北京邀请赛 Just  String http://www.bnuoj.com/v3/problem_show.php?pid=34990 两道题同样的做法,题目基本内容是找到A的字串中和B串长度一样,且不同的字符个数不超过k个的置. 以hihocoder 1084为例, 是求有多少个A的字串的,与B串长度一样,且不同的字符个数不超过k. 分析:预处理hash,然后对每个字…

A. A Matrix 点击打开链接 构造,结论是从第一行開始往下产生一条曲线,使得这条区间最长且从上到下递减, #include <cstdio> #include <cstring> #include <algorithm> #include <iostream> #include <stdio.h> #include <vector> #include <set> using namespace std; #defi…

题目 Source http://acm.split.hdu.edu.cn/showproblem.php?pid=5863 Description cjj has k kinds of characters the number of which are infinite. He wants to build two strings with the characters. The lengths of the strings are both equal to n. cjj also def…

Description In our daily life we often use 233 to express our feelings. Actually, we may say 2333, 23333, or 233333 ... in the same meaning. And here is the question: Suppose we have a matrix called 233 matrix. In the first line, it would be 233, 233…

题目链接 https://nanti.jisuanke.com/t/38222 题意: 定义函数: $$F(n)=\left\{\begin{aligned}1, \quad n=1,2 \\F(n-1)+F(n-2),\quad n\geq3 \quad \end{aligned}\right.$$ 给定一个W 找到一个字典序最小的集合S使得 $$W=\sum_{f\in S}F(F(f))$$ $1\leq  T\leq 10$ $1\leq  W\leq 10^{100,000}$ 解析:…