给定一个字符串,求本质不同排名第k小的子串 Solution 后缀自动机上每条路径对应一个本质不同的子串 按照 TRANS 图的拓扑序,DP 计算出每个点发出多少条路径 (注意区别 TRANS 图的拓扑序和后缀链接的拓扑序) 然后暴力 26 分询问即可 #include <bits/stdc++.h> using namespace std; const int Maxn = 2000005; struct Suffix_Automata { int maxlen[Maxn], trans[M…

传送门 解题思路 首先建\(sam\),然后在拓扑序上\(dp\)一下,把每个点的路径数算出来,然后统计答案时就在自动机上\(dfs\)一下,仿照平衡树那样找第\(k\)小. 代码 #include<iostream> #include<cstdio> #include<cstring> #include<cmath> using namespace std; const int MAXN = 90005; inline int rd(){ int x=0,…

SUBLEX - Lexicographical Substring Search Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his skills so he gave him a string S and asked him Q questions…

题意:给一个长度不超过90000的串S,每次询问它的所有不同子串中,字典序第K小的,询问不超过500个. 第一道自己做的1A的SAM啦啦啦 很简单,建SAM后跑kth就行了 也需要按val基数排序倒着推出来d[s]状态s的后继子串个数 跑kth的时候判断d[v]>=k的时候就跑到v,并且k应该是--哦,因为一个子串过去了 #include <iostream> #include <cstdio> #include <cstring> #include <al…

Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his skills so he gave him a string S and asked him Q questions of the form: If all distinct substrings o…

spoj 7258 Lexicographical Substring Search (后缀自动机) 题意:给出一个字符串,长度为90000.询问q次,每次回答一个k,求字典序第k小的子串. 解题思路:构造出sam后,类似splay求前驱的做法,不断的逼近答案.我们知道,sam里从s走到某一节点即为一个子串,所以我们在每个节点下记录一个cnt,表示该节点下,能走到的节点有多少个.那么我们在求第k小的子串时,就往下走,枚举当前节点下的26字母节点,若枚举到的节点的cnt+1>=k那么就往该节点走,…

题目传送门 传送门I 传送门II 题目大意 给定一个字符串,多次询问它的第$k$大本质不同的子串,输出它. 考虑后缀Trie.依次考虑每个后缀新增的本质不同的子串个数,显然,它是$n - sa[i] - height[i]$. 求出$height$数组后,求一求本质不同的子串个数的前缀和,可以对每个询问二分. 这里可以直接离线,$O(n + m)$扫一扫就好了. Code /** * SPOJ * Problem#SUBLEX * Accepted * Time: 30ms * Memory:…

给你一个字符串,然后询问它第k小的factor,坑的地方在于spoj实在是太慢了,要加各种常数优化,字符集如果不压缩一下必t.. #pragma warning(disable:4996) #include<cstring> #include<string> #include<iostream> #include<cmath> #include<vector> #include<algorithm> #define maxn 9005…

\(\color{#0066ff}{ 题目描述 }\) 给定一个字符串,求排名第k小的串 \(\color{#0066ff}{输入格式}\) 第一行给定主串(len<=90000) 第二行给定询问个数T<=500 随后给出T行T个询问,每次询问排名第k小的串,范围在int内 \(\color{#0066ff}{输出格式}\) 对于每一个询问,输出T行,每行为排名第k小的串 \(\color{#0066ff}{输入样例}\) aaa 2 2 3 \(\color{#0066ff}{输出样例}\)…

Dicription Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his skills so he gave him a string S and asked him Q questions of the form: If all distinct s…