E. Little Elephant and Strings time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output The Little Elephant loves strings very much. He has an array a from n strings, consisting of lowercase Englis…

题意:有n个串,询问每个串有多少子串在n个串中出现了至少k次. 题解:sam,每个节点开一个set维护该节点的字符串有哪几个串,启发式合并set,然后在sam上走一遍该串,对于每个可行的串,所有的fail都是可行的直接加上len,不可行就往fail上跳. 被for(int i=0;s[i];i++)给骚死了,一直tle.... //#pragma GCC optimize(2) //#pragma GCC optimize(3) //#pragma GCC optimize(4) //#prag…

C. Little Elephant and Shifts Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/220/C Description The Little Elephant has two permutations a and b of length n, consisting of numbers from 1 to n, inclusive. Let's de…

题目链接: http://codeforces.com/problemset/problem/258/B B. Little Elephant and Elections time limit per test2 secondsmemory limit per test256 megabytes 问题描述 There have recently been elections in the zoo. Overall there were 7 main political parties: one…

A. Little Elephant and Rozdil 求\(n\)个数中最小值的个数及下标. B. Little Elephant and Sorting \[\sum_{i=1}^{n-1}{max(0, a_i-a_{i+ 1})}\] C. Little Elephant and Interval 问题转化成求\([1,n]\)范围内满足题意的数的个数. 假设\(n\)的位数为\(L\),当\(L \gt 2\)时,若\(x\)的位数小于\(L\),则除了首位和末位以外,其余位任意取…

Description The Little Elephant very much loves sums on intervals. This time he has a pair of integers l and r (l ≤ r). The Little Elephant has to find the number of such integers x (l ≤ x ≤ r), that the first digit of integer x equals the last one (…

Description The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of…

Description The Little Elephant loves Ukraine very much. Most of all he loves town Rozdol (ukr. "Rozdil"). However, Rozdil is dangerous to settle, so the Little Elephant wants to go to some other town. The Little Elephant doesn't like to spend m…

B. Little Elephant and Array time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output The Little Elephant loves playing with arrays. He has array a, consisting of n positive integers, indexed from…

数位DP部分,不是很难.DP[i][j]前i位j个幸运数的个数.枚举写的有点搓... #include <cstdio> #include <cstring> using namespace std; #define LL __int64 #define MOD 1000000007 ][]; ],num; ]; int dfs(int pos,int pre,int bound) { int ans,i,end; ans = ; ) ; ) return dp[pos][pre]…