Codeforces Round #396 (Div. 2) C
Mahmoud wrote a message s of length n. He wants to send it as a birthday present to his friend Moaz who likes strings. He wrote it on a magical paper but he was surprised because some characters disappeared while writing the string. That's because this magical paper doesn't allow character number i in the English alphabet to be written on it in a string of length more than ai. For example, if a1 = 2 he can't write character 'a' on this paper in a string of length 3 or more. String "aa" is allowed while string "aaa" is not.
Mahmoud decided to split the message into some non-empty substrings so that he can write every substring on an independent magical paper and fulfill the condition. The sum of their lengths should be n and they shouldn't overlap. For example, if a1 = 2 and he wants to send string "aaa", he can split it into "a" and "aa" and use 2 magical papers, or into "a", "a" and "a" and use 3 magical papers. He can't split it into "aa" and "aa" because the sum of their lengths is greater than n. He can split the message into single string if it fulfills the conditions.
A substring of string s is a string that consists of some consecutive characters from string s, strings "ab", "abc" and "b" are substrings of string "abc", while strings "acb" and "ac" are not. Any string is a substring of itself.
While Mahmoud was thinking of how to split the message, Ehab told him that there are many ways to split it. After that Mahmoud asked you three questions:
- How many ways are there to split the string into substrings such that every substring fulfills the condition of the magical paper, the sum of their lengths is n and they don't overlap? Compute the answer modulo 109 + 7.
- What is the maximum length of a substring that can appear in some valid splitting?
- What is the minimum number of substrings the message can be spit in?
Two ways are considered different, if the sets of split positions differ. For example, splitting "aa|a" and "a|aa" are considered different splittings of message "aaa".
The first line contains an integer n (1 ≤ n ≤ 103) denoting the length of the message.
The second line contains the message s of length n that consists of lowercase English letters.
The third line contains 26 integers a1, a2, ..., a26 (1 ≤ ax ≤ 103) — the maximum lengths of substring each letter can appear in.
Print three lines.
In the first line print the number of ways to split the message into substrings and fulfill the conditions mentioned in the problem modulo 109 + 7.
In the second line print the length of the longest substring over all the ways.
In the third line print the minimum number of substrings over all the ways.
3
aab
2 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
3
2
2
10
abcdeabcde
5 5 5 5 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
401
4
3
In the first example the three ways to split the message are:
- a|a|b
- aa|b
- a|ab
The longest substrings are "aa" and "ab" of length 2.
The minimum number of substrings is 2 in "a|ab" or "aa|b".
Notice that "aab" is not a possible splitting because the letter 'a' appears in a substring of length 3, while a1 = 2.
题意:说的是字符串分割,不过是有条件的,一个字符在一个分割区域是不能出现超过ai次,问能分几次,每个区间最长多少,最短多少
解法:
1 dp[i]表示到第i位置能分割多少次,和它前i-j的位置有关,j<=i(表示能分割的长度)i-j+1是距离i有j个长度的地方(在i的左边)
2 每次讨论j都需要验证是不是满足条件,是的话就是+dp[i-j]
3 最长的距离当然是比较j喽,最短的话比较Min[i-j]+1和Min[i]
#include<bits/stdc++.h>
using namespace std;
int n;
char s[];
int mod=1e9+;
long long dp[];
long long a[];
long long Min[];
int solve(int x,int y,int len){
int Len=len;
for(int i=x;i<=y;i++){
if(Len>a[s[i]-'a']){
return ;
}
}
return ;
}
int main(){
cin>>n;
cin>>s+;
for(int i=;i<;i++){
cin>>a[i];
}
dp[]=;
int maxn=;
for(int i=;i<=n;i++){
Min[i]=1e9;
for(int j=;j<=i;j++){
if(solve(i-j+,i,j)){
dp[i]+=(dp[i-j]%mod);
dp[i]%=mod;
maxn=max(j,maxn);
Min[i]=min(Min[i-j]+,Min[i]);
}
}
}
cout<<dp[n]%mod<<endl;
cout<<maxn<<endl;
cout<<Min[n]<<endl;
return ;
}
Codeforces Round #396 (Div. 2) C的更多相关文章
- Codeforces Round #396 (Div. 2) D. Mahmoud and a Dictionary 并查集
D. Mahmoud and a Dictionary 题目连接: http://codeforces.com/contest/766/problem/D Description Mahmoud wa ...
- Codeforces Round #396 (Div. 2) A,B,C,D,E
A. Mahmoud and Longest Uncommon Subsequence time limit per test 2 seconds memory limit per test 256 ...
- Codeforces Round #396 (Div. 2) A B C D 水 trick dp 并查集
A. Mahmoud and Longest Uncommon Subsequence time limit per test 2 seconds memory limit per test 256 ...
- Codeforces Round #396 (Div. 2) D. Mahmoud and a Dictionary
地址:http://codeforces.com/contest/766/problem/D 题目: D. Mahmoud and a Dictionary time limit per test 4 ...
- Codeforces Round #396 (Div. 2) D
Mahmoud wants to write a new dictionary that contains n words and relations between them. There are ...
- Codeforces Round #396 (Div. 2) E. Mahmoud and a xor trip dfs 按位考虑
E. Mahmoud and a xor trip 题目连接: http://codeforces.com/contest/766/problem/E Description Mahmoud and ...
- Codeforces Round #396 (Div. 2) C. Mahmoud and a Message dp
C. Mahmoud and a Message 题目连接: http://codeforces.com/contest/766/problem/C Description Mahmoud wrote ...
- Codeforces Round #396 (Div. 2) B. Mahmoud and a Triangle 贪心
B. Mahmoud and a Triangle 题目连接: http://codeforces.com/contest/766/problem/B Description Mahmoud has ...
- Codeforces Round #396 (Div. 2) A. Mahmoud and Longest Uncommon Subsequence 水题
A. Mahmoud and Longest Uncommon Subsequence 题目连接: http://codeforces.com/contest/766/problem/A Descri ...
- Codeforces Round #396 (Div. 2) E. Mahmoud and a xor trip
地址:http://codeforces.com/contest/766/problem/E 题目: E. Mahmoud and a xor trip time limit per test 2 s ...
随机推荐
- Android系统DHCP问题【转】
本文转载自:http://blog.csdn.net/tankai19880619/article/details/42972551 一.现象 12小时压测wifi连接后,发现网络连接中断:相关log ...
- ffplay 一些好玩的filter
添加字幕:ffplay -vf drawtext="fontfile=arial.ttf: text='Test Text': x=100: y=300: \ fontsize=48: fo ...
- 程序员代码面试指南:IT名企算法与数据结构题目最优解
第1章栈和队列 1设计一个有getMin功能的栈(士★☆☆☆) 1由两个栈组成的队列(尉★★☆☆) 5如何仅用递归函数和栈操作逆序一个栈(尉★★☆☆) 8猫狗队列(士★☆☆☆)10用一个栈实现另一 ...
- 开发自己的composer包
1. 创建一个开发目录 mkdir project cd project 2. 利用composer生成一个composer.json composer init > Welcome to th ...
- 「ZJOI2007」「LuoguP1169」棋盘制作(并查集
题目描述 国际象棋是世界上最古老的博弈游戏之一,和中国的围棋.象棋以及日本的将棋同享盛名.据说国际象棋起源于易经的思想,棋盘是一个8×88 \times 88×8大小的黑白相间的方阵,对应八八六十四卦 ...
- [CTSC 2018] 混合果汁
[题目链接] https://www.lydsy.com/JudgeOnline/problem.php?id=5343 [算法] 对于每组询问 , 首先二分答案 显然 , 最优策略为优先选择价格低的 ...
- iOS 中这些是否熟练掌握——(1)
声明:本篇博文是作者原创作品.参考1 参考2 参考3 参考4 参考5 参考6 关于网上一些关于iOS资料,自己通过学习做了一些整理,这里仅仅作为笔记,方便自己学习使用,加深理解. 1.什么是 ...
- WebService完成文件上传下载
由于开发需要使用webservice,第一个接触的工具叫axis2.项目开发相关jar下载. service端: 启动类: import java.net.InetAddress; import ja ...
- Ubuntu系统多屏显示
Ubuntu系统多屏显示参见: 第一个为笔记本屏幕,第二个为外接屏幕 http://www.linuxidc.com/Linux/2014-06/103677.htm http://www.linux ...
- 2.4 hive创建表实例讲解
一.create table ## 员工表 create table IF NOT EXISTS default.emp( empno int, ename string, job string, m ...