Arithmancy is Draco Malfoy's favorite subject, but what spoils it for him is that Hermione Granger is in his class, and she is better than him at it.  Prime numbers are of mystical importance in Arithmancy, and Lucky Numbers even more so. Lucky Numbe…

Arithmancy is Draco Malfoy's favorite subject, but what spoils it for him is that Hermione Granger is in his class, and she is better than him at it. Prime numbers are of mystical importance in Arithmancy, and Lucky Numbers even more so. Lucky Number…

The first two consecutive numbers to have two distinct prime factors are: 14 = 2  7 15 = 3  5 The first three consecutive numbers to have three distinct prime factors are: 644 = 2²  7  23 645 = 3  5  43 646 = 2  17  19. Find the first four consecutiv…

[SPOJ]Distinct Substrings(后缀自动机) 题面 Vjudge 题意:求一个串的不同子串的数量 题解 对于这个串构建后缀自动机之后 我们知道每个串出现的次数就是\(right/endpos\)集合的大小 但是实际上我们没有任何必要减去不合法的数量 我们只需要累加每个节点表示的合法子串的数量即可 这个值等于\(longest-shortest+1=longest-parent.longest\) #include<iostream> #include<cstdio&g…

[SPOJ]Distinct Substrings/New Distinct Substrings(后缀数组) 题面 Vjudge1 Vjudge2 题解 要求的是串的不同的子串个数 两道一模一样的题目 其实很容易: 总方案-不合法方案数 对于串进行后缀排序后 不合法方案数=相邻两个串的不合法方案数的和 也就是\(height\)的和 所以\[ans=\frac{n(n+1)}{2}-\sum_{i=1}^{len}height[i]\] #include<iostream> #include…

[SPOJ]Distinct Substrings 求不同子串数量 统计每个点有效的字符串数量(第一次出现的) \(\sum\limits_{now=1}^{nod}now.longest-parents.longest\) My complete code #include<bits/stdc++.h> using namespace std; typedef long long LL; const LL maxn=3000; LL nod,last,n,T; LL len[maxn],fa…

694. Distinct Substrings Problem code: DISUBSTR   Given a string, we need to find the total number of its distinct substrings. Input T- number of test cases. T<=20;Each test case consists of one string, whose length is <= 1000 Output For each test c…

Distinct Substrings Time Limit: 1000ms Memory Limit: 262144KB This problem will be judged on SPOJ. Original ID: DISUBSTR64-bit integer IO format: %lld      Java class name: Main   Given a string, we need to find the total number of its distinct subst…

The first two consecutive numbers to have two distinct prime factors are: 14 = 2 × 7 15 = 3 × 5 The first three consecutive numbers to have three distinct prime factors are: 644 = 2² × 7 × 23 645 = 3 × 5 × 43 646 = 2 × 17 × 19. Find the first four co…

[题目链接] http://www.spoj.com/problems/SUBST1/ [题目大意] 给出一个串,求出不相同的子串的个数. [题解] 对原串做一遍后缀数组,按照后缀的名次进行遍历, 每个后缀对答案的贡献为n-sa[i]+1-h[i], 因为排名相邻的后缀一定是公共前缀最长的, 那么就可以有效地通过LCP去除重复计算的子串. [代码] #include <cstdio> #include <cstring> #include <algorithm> usi…