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. E20170624-ts

    stateless adj. 无国家的,无国籍的; groupware 群件 cookie  n. 饼干; 小甜点; 吸引人的年轻妇女; 甜面包; session  n. 开会,会议; (法庭的) 开 ...

  2. Sara Cope关于text-shadow的介绍

    作者:Sara Cope p { text-shadow: 1px 1px 1px #000; } 你可以通过逗号“,”应用多个文本阴影. p { text-shadow: 1px 1px 1px # ...

  3. akka设计模式系列-Backend模式

    上一节我们介绍了Akka使用的基本模式,简单点来说就是,发消息给actor,处理结束后返回消息.但这种模式有个缺陷,就是一旦某个消息处理的比较慢,就会阻塞后面所有消息的处理.那么有没有方法规避这种阻塞 ...

  4. linux命令大杂烩之网络管理

    在Linux中curl是一个利用URL规则在命令行下工作的文件传输工具,可以说是一款很强大的http命令行工具.它支持文件的上传和下载,是综合传输工具,但按传统,习惯称url为下载工具. 作为一款强力 ...

  5. cocos2d-x 调用第三方so文件

    一:假设.so文件名称 : libhi.so 1.jni文件下创建一个prebuilt 2.android.mk文件中找到  include $(CLEAR_VARS), 在这句后面添加如下代码 in ...

  6. NHibernate学习(零)-本次学习遇到的错误汇总

    问题一: "System.TypeInitializationException"类型的未经处理的异常在 KimismeDemo.exe 中发生 其他信息: "NHibe ...

  7. java学习笔记_BeatBox(GUI部分)

    import java.awt.*; import javax.swing.*; public class BeatBox { JFrame theFrame; JPanel mainPanel; S ...

  8. 不用float也可以让div横向显示

    display: inline-block; vertical-align: top; 就这两个属性,给div设置上,div就不会换行显示啦,而且还不影响横向的其他元素的显示.

  9. CentOS7阿里云服务器,python程序requests无法正常post网站(报502)

    问题描述: 使用jenkins构建接口自动化测试时,发现新增加的接口case不能访问通,会报502错误(本地可以跑通,在测试服就会502)解决的思路: 缩小调试范围(去掉jenkins db环境,将问 ...

  10. CAD调用导角命令,并返回导角的圆弧对象

    主要用到函数说明: _DMxDrawX::SendStringToExecuteFun 把命令当着函数执行,可以传参数,详细说明如下: 参数 说明 IDispatch* pParam 命令参数,IMx ...