博客
关于我
1045 Favorite Color Stripe
阅读量:430 次
发布时间:2019-03-06

本文共 2668 字,大约阅读时间需要 8 分钟。

Eva is trying to make her own color stripe out of a given one. She would like to keep only her favorite colors in her favorite order by cutting off those unwanted pieces and sewing the remaining parts together to form her favorite color stripe.

It is said that a normal human eye can distinguish about less than 200 different colors, so Eva's favorite colors are limited. However the original stripe could be very long, and Eva would like to have the remaining favorite stripe with the maximum length. So she needs your help to find her the best result.

Note that the solution might not be unique, but you only have to tell her the maximum length. For example, given a stripe of colors {2 2 4 1 5 5 6 3 1 1 5 6}. If Eva's favorite colors are given in her favorite order as {2 3 1 5 6}, then she has 4 possible best solutions {2 2 1 1 1 5 6}, {2 2 1 5 5 5 6}, {2 2 1 5 5 6 6}, and {2 2 3 1 1 5 6}.

Input Specification:

Each input file contains one test case. For each case, the first line contains a positive integer N (≤) which is the total number of colors involved (and hence the colors are numbered from 1 to N). Then the next line starts with a positive integer M (≤) followed by M Eva's favorite color numbers given in her favorite order. Finally the third line starts with a positive integer L (≤) which is the length of the given stripe, followed by L colors on the stripe. All the numbers in a line a separated by a space.

Output Specification:

For each test case, simply print in a line the maximum length of Eva's favorite stripe.

Sample Input:

65 2 3 1 5 612 2 2 4 1 5 5 6 3 1 1 5 6
 

Sample Output:

7

题意:

  给出一组favorite color的序列,和一组colors stripe的序列,要求在color stripe序列中找出满足favorite color序列的子串,子串中元素可以重复,只要满足子串颜色的序列和喜欢颜色的序列相同即可。

思路:

  这道题应该用DP来解决,dp[i][j] : 表示在喜欢颜色的序列中以i为下标的颜色结尾,在colors stripe中[:j]中满足喜欢颜色[:i]序列的子串长度。状态转移方程: dp[i][j] = max(dp[i-1])[j], dp[i]][j-1]]; dp[i-1][j]表在colors stripe中[:j]相等的情况下,favorite color的下表向后移动一位,可能是子串长度改变。 dp[i][j-1] : 表示在favorite color中[:i]相等的情况下color stripe下标向后移动一位可能使子串长度发生改变。

Code:

1 #include 
2 3 using namespace std; 4 5 int main() { 6 int n, m, l; 7 cin >> n >> m; 8 vector
colors(n + 1); 9 set
found;10 for (int i = 1; i <= m; ++i) cin >> colors[i];11 cin >> l;12 vector
stripe(l + 1);13 for (int i = 1; i <= l; ++i) cin >> stripe[i];14 vector
> dp(n + 1, vector
(l + 1, 0));15 for (int i = 1; i <= n; ++i) {16 for (int j = 1; j <= l; ++j) {17 dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);18 if (colors[i] == stripe[j]) dp[i][j]++;19 }20 }21 cout << dp[n][l] << endl;22 return 0;23 }

 

转载地址:http://lstuz.baihongyu.com/

你可能感兴趣的文章
mysql 使用sql文件恢复数据库
查看>>
mysql 修改默认字符集为utf8
查看>>
Mysql 共享锁
查看>>
MySQL 内核深度优化
查看>>
mysql 内连接、自然连接、外连接的区别
查看>>
mysql 写入慢优化
查看>>
mysql 分组统计SQL语句
查看>>
Mysql 分页
查看>>
Mysql 分页语句 Limit原理
查看>>
MySql 创建函数 Error Code : 1418
查看>>
MySQL 创建新用户及授予权限的完整流程
查看>>
mysql 创建表,不能包含关键字values 以及 表id自增问题
查看>>
mysql 删除日志文件详解
查看>>
mysql 判断表字段是否存在,然后修改
查看>>
MySQL 到底能不能放到 Docker 里跑?
查看>>
mysql 前缀索引 命令_11 | Mysql怎么给字符串字段加索引?
查看>>
mysql 协议的退出命令包及解析
查看>>
mysql 取表中分组之后最新一条数据 分组最新数据 分组取最新数据 分组数据 获取每个分类的最新数据
查看>>
mysql 四种存储引擎
查看>>
MySQL 基础模块的面试题总结
查看>>