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中having的用法
查看>>
MySQL中interactive_timeout和wait_timeout的区别
查看>>
mysql中int、bigint、smallint 和 tinyint的区别、char和varchar的区别详细介绍
查看>>
mysql中json_extract的使用方法
查看>>
mysql中json_extract的使用方法
查看>>
mysql中kill掉所有锁表的进程
查看>>
mysql中like % %模糊查询
查看>>
MySql中mvcc学习记录
查看>>
mysql中null和空字符串的区别与问题!
查看>>
MySQL中ON DUPLICATE KEY UPDATE的介绍与使用、批量更新、存在即更新不存在则插入
查看>>
MYSQL中TINYINT的取值范围
查看>>
MySQL中UPDATE语句的神奇技巧,让你操作数据库如虎添翼!
查看>>
Mysql中varchar类型数字排序不对踩坑记录
查看>>
MySQL中一条SQL语句到底是如何执行的呢?
查看>>
MySQL中你必须知道的10件事,1.5万字!
查看>>
MySQL中使用IN()查询到底走不走索引?
查看>>
Mysql中使用存储过程插入decimal和时间数据递增的模拟数据
查看>>
MySql中关于geometry类型的数据_空的时候如何插入处理_需用null_空字符串插入会报错_Cannot get geometry object from dat---MySql工作笔记003
查看>>
mysql中出现Incorrect DECIMAL value: '0' for column '' at row -1错误解决方案
查看>>
mysql中出现Unit mysql.service could not be found 的解决方法
查看>>