CRAN02 - Roommate Agreement Leonard was always sickened by how Sheldon considered himself better than him. To decide once and for all who is better among them they decided to ask each other a puzzle. Sheldon pointed out that according to Roommate Agr…

[题目链接] http://www.spoj.com/problems/TLE/en/ [题目大意] 给出n个数字c,求非负整数序列a,满足a<2^m 并且有a[i]&a[i+1]=0,对于每个a[i],要保证a[i]不是c[i]的倍数, 求这样的a[i]序列的个数 [题解] 我们用dp[i]表示以i为结尾的方案数, 我们发现要满足a[i]&a[i+1]=0,则dp[i]是从上一次结果中所有满足i&j=0的地方转移过来的 i&j=0即i&(~j)=i,即i为~…

题目链接 \(Description\) 给定长为\(n\)的数组\(c_i\)和\(m\),求长为\(n\)的序列\(a_i\)个数,满足:\(c_i\not\mid a_i,\quad a_i\&a_{i+1}=0\). \(n\leq 50,m\leq 15,0\leq a_i<2^m,0<c_i\leq 2^m\). \(Solution\) DP.限制都是与值有关的,所以令\(f_i\)表示以\(i\)这个数结尾的序列\(a\)的个数. 转移即\(f_i=\sum_{j,i\…

Problem description. The Fibonacci numbers defined as f(n) = f(n-1) + f(n-2) where f0 = 0 and f1 = 1. We define a function as follows D(n,x) = x + x^2 + 2x^3 + 3x^4 + 5x^5 + 8x^6 +...+f(n)x^n Given two integers n and x, you need to compute D(n,x) sin…

题目 vjudge URL:Counting Divisors (square) Let σ0(n)\sigma_0(n)σ0​(n) be the number of positive divisors of nnn. For example, σ0(1)=1\sigma_0(1) = 1σ0​(1)=1, σ0(2)=2\sigma_0(2) = 2σ0​(2)=2 and σ0(6)=4\sigma_0(6) = 4σ0​(6)=4. Let S2(n)=∑i=1nσ0(i2).S_2(n…

Code: #include <cstdio> #include <algorithm> #include <cstring> #define setIO(s) freopen(s".in","r",stdin) #define maxn 1000000 #define ll long long using namespace std; char str[maxn]; int arr[maxn],pos[maxn],x[maxn]…

2588: Spoj 10628. Count on a tree Time Limit: 12 Sec  Memory Limit: 128 MBSubmit: 5217  Solved: 1233[Submit][Status][Discuss] Description 给定一棵N个节点的树,每个点有一个权值,对于M个询问(u,v,k),你需要回答u xor lastans和v这两个节点间第K小的点权.其中lastans是上一个询问的答案,初始为0,即第一个询问的u是明文. Input 第一…

题目链接:http://www.spoj.com/problems/REPEATS/en/ 题意:首先定义了一个字符串的重复度.即一个字符串由一个子串重复k次构成.那么最大的k即是该字符串的重复度.现在给定一个长度为n的字符串,求最大重复次数. 思路:根据<<后缀数组——处理字符串的有力工具>>的思路,先穷举长度L,然后求长度为L 的子串最多能连续出现几次.首先连续出现1 次是肯定可以的,所以这里只考虑至少2 次的情况.假设在原字符串中连续出现2 次,记这个子字符串为S,那么S 肯…

题目链接:http://www.spoj.com/problems/DISUBSTR/en/ 题意:给定一个字符串,求不相同的子串个数. 思路:直接根据09年oi论文<<后缀数组——出来字符串的有力工具>>的解法. 还有另一种思想:总数为n*(n-1)/2,height[i]是两个后缀的最长公共前缀,所以用总数-height[i]的和就是答案 #define _CRT_SECURE_NO_DEPRECATE #include<iostream> #include<…

COT - Count on a tree #tree You are given a tree with N nodes.The tree nodes are numbered from 1 to N.Each node has an integer weight. We will ask you to perform the following operation: u v k : ask for the kth minimum weight on the path from node u …