C. An impassioned circulation of affection
time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Nadeko's birthday is approaching! As she decorated the room for the party, a long garland of Dianthus-shaped paper pieces was placed on a prominent part of the wall. Brother Koyomi will like it!

Still unsatisfied with the garland, Nadeko decided to polish it again. The garland has n pieces numbered from 1 to n from left to right, and the i-th piece has a colour si, denoted by a lowercase English letter. Nadeko will repaint at most m of the pieces to give each of them an arbitrary new colour (still denoted by a lowercase English letter). After this work, she finds out all subsegments of the garland containing pieces of only colour c — Brother Koyomi's favourite one, and takes the length of the longest among them to be the Koyomity of the garland.

For instance, let's say the garland is represented by "kooomo", and Brother Koyomi's favourite colour is "o". Among all subsegments containing pieces of "o" only, "ooo" is the longest, with a length of 3. Thus the Koyomity of this garland equals 3.

But problem arises as Nadeko is unsure about Brother Koyomi's favourite colour, and has swaying ideas on the amount of work to do. She has q plans on this, each of which can be expressed as a pair of an integer mi and a lowercase letter ci, meanings of which are explained above. You are to find out the maximum Koyomity achievable after repainting the garland according to each plan.

Input

The first line of input contains a positive integer n (1 ≤ n ≤ 1 500) — the length of the garland.

The second line contains n lowercase English letters s1s2... sn as a string — the initial colours of paper pieces on the garland.

The third line contains a positive integer q (1 ≤ q ≤ 200 000) — the number of plans Nadeko has.

The next q lines describe one plan each: the i-th among them contains an integer mi (1 ≤ mi ≤ n) — the maximum amount of pieces to repaint, followed by a space, then by a lowercase English letter ci — Koyomi's possible favourite colour.

Output

Output q lines: for each work plan, output one line containing an integer — the largest Koyomity achievable after repainting the garland according to it.

Examples
input
6
koyomi
3
1 o
4 o
4 m
output
3
6
5
input
15
yamatonadeshiko
10
1 a
2 a
3 a
4 a
5 a
1 b
2 b
3 b
4 b
5 b
output
3
4
5
7
8
1
2
3
4
5
input
10
aaaaaaaaaa
2
10 b
10 z
output
10
10
Note

In the first sample, there are three plans:

  • In the first plan, at most 1 piece can be repainted. Repainting the "y" piece to become "o" results in "kooomi", whose Koyomity of 3 is the best achievable;
  • In the second plan, at most 4 pieces can be repainted, and "oooooo" results in a Koyomity of 6;
  • In the third plan, at most 4 pieces can be repainted, and "mmmmmi" and "kmmmmm" both result in a Koyomity of 5.
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<sstream>
#include<algorithm>
#include<queue>
#include<deque>
#include<iomanip>
#include<vector>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<fstream>
#include<memory>
#include<list>
#include<string>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
#define MAXN 1590
#define N 26
#define MOD 1000000
#define INF 1000000009
const double eps = 1e-;
const double PI = acos(-1.0);
/*
一开始的思路:线段相连,一直求相连的长度最长的两个线段增加的c字符数目,减少m的次数,一直到无法增加
编程复杂,时间复杂度高
题解:
首先 目的是让要求的字符c的连续串长度最长,那么我们应该在一个c的连续串附近交换字符,否则无法增大最优解
对于每一个字符c和长度,枚举出需要交换m个c字符的时候最长连续序列的长度然后直接查询!
*/
int ans[N][MAXN], l ,n;
char s[MAXN];
int main()
{
scanf("%d", &l);
scanf("%s", s);
for (int c = ; c < N; c++)
{
for (int i = ; i < l; i++)
{
int dif = ;
for (int j = i; j < l; j++)
{
if (s[j] != c + 'a')
dif++;
ans[c][dif] = max(ans[c][dif], j - i + );
}
}
for (int i = ; i <= l; i++)
ans[c][i] = max(ans[c][i], ans[c][i - ]);
}
scanf("%d", &n);
int m;
char c;
while (n--)
{
scanf("%d %c", &m, &c);
m = min(l, m);
printf("%d\n", ans[c-'a'][m]);
}
}

Codeforces Round #418 (Div. 2) C. An impassioned circulation of affection的更多相关文章

  1. Codeforces Round #418 (Div. 2) D. An overnight dance in discotheque

    Codeforces Round #418 (Div. 2) D. An overnight dance in discotheque 题意: 给\(n(n <= 1000)\)个圆,圆与圆之间 ...

  2. Codeforces Round #418 (Div. 2).C two points

    C. An impassioned circulation of affection time limit per test 2 seconds memory limit per test 256 m ...

  3. Codeforces Round #418 (Div. 2) A+B+C!

    终判才知道自己失了智.本场据说是chinese专场,可是请允许我吐槽一下题意! A. An abandoned sentiment from past shabi贪心手残for循环边界写错了竟然还过了 ...

  4. Codeforces Round #418 (Div. 2)

    A: 不细心WA了好多次 题意:给你一个a序列,再给你个b序列,你需要用b序列中的数字去替换a序列中的0,如果能够替换,则需要判断a是否能构成一个非递增的序列,a,b中所有的数字不会重复 思路:就是一 ...

  5. Codeforces Round #418 (Div. 2) B. An express train to reveries

    time limit per test 1 second memory limit per test 256 megabytes input standard input output standar ...

  6. Codeforces Round #418 (Div. 2)D

    给n个圆要么包含,要么相分离,没有两个公共点,当成一棵树,把包含的面积大的放在上面 如图最上面的par记为-1,level记为0,当par==-1||level==1时就加否则减, 就是第一,二层先加 ...

  7. Codeforces Round #418 (Div. 2) C

    Description Nadeko's birthday is approaching! As she decorated the room for the party, a long garlan ...

  8. Codeforces Round #418 (Div. 2) B

    Description Sengoku still remembers the mysterious "colourful meteoroids" she discovered w ...

  9. Codeforces Round #418 (Div. 2) A

    Description A few years ago, Hitagi encountered a giant crab, who stole the whole of her body weight ...

随机推荐

  1. action="post" 、 servletconfig 、 servletcontext 、getPrintWiter() 、context-param、 init-param(第一个完整的servlet)

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <hea ...

  2. day03_12/13/2016_bean的管理之初始化和销毁

  3. UNIX环境高级编程--3

    文件IO 函数lseek: 每个打开文件都有一个与其相关联的“当前文件偏移量”,用来度量从文件开始处计算的字节数.除非指定O_APPEND选项,否则该偏移量被置为0.如果文件描述符指向的是一个管道.F ...

  4. 【转】Linux中的LVM

    转自:http://www.cnblogs.com/net2012/p/3365904.html 逻辑卷管理器,通过将另外一个硬盘上的分区加到已有文件系统,来动态地向已有文件系统添加空间的方法. 逻辑 ...

  5. Manacher 学习笔记

    \(\\\) \(Manacher\) 一种常用的字符串算法,用于处理一些回文字符相关的问题. 回文串:从前向后和从后向前输出一致. 回文中心:以这里开始,每次向外左右各扩展一个字符得到的回文串的中心 ...

  6. 怎么搭建Hibernate对象持久化框架?

    DBC:(Java Data Base Connectivity)java数据库连接 java.sql包提供JDBC API,可通过它编写访问数据库的程序代码.其中常用的接口和类包括下面内容: Dri ...

  7. N的阶乘末尾有多少个零?

    在创联ifLab的招新问答卷上看到这么一题 核心问题是: 求N!(N的阶乘)的末尾有多少个零? 由于在N特别大的时候强行算出N!是不可能的,所以肯定要另找方法解决了. 首先,为什么末尾会有0?因为2* ...

  8. 一款批量linux管理工具batchshell

    BatchShell是什么? BatchShell是一款基于SSH2的批量文件传输及命令执行工具,它可以同时传输文件到多台远程服务器以及同时对多台远程服务器执行命令.BatchShell基于原生的sh ...

  9. CNN结构:Windows使用FasterRCNN-C++版本

    参考文章:Windows下VS2013 C++编译测试faster-rcnn. 本文与作者的所写方法有些许不同,欲速则不达,没有按照作者的推荐方法,绕了个弯弯. Windows版本纯C++版本的Fas ...

  10. CSS居中布局方案

    基本结构 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF- ...