题目
Mahmoud wants to send a message to his friend Ehab. Their language consists of n words numbered from 1 to n. Some words have the same meaning so there are k groups of words such that all the words in some group have the same meaning.
Mahmoud knows that the i-th word can be sent with cost ai. For each word in his message, Mahmoud can either replace it with another word of the same meaning or leave it as it is. Can you help Mahmoud determine the minimum cost of sending the message?
The cost of sending the message is the sum of the costs of sending every word in it.
Input
The first line of input contains integers n, k and m (1 ≤ k ≤ n ≤ 105, 1 ≤ m ≤ 105) — the number of words in their language, the number of groups of words, and the number of words in Mahmoud’s message respectively.
The second line contains n strings consisting of lowercase English letters of length not exceeding 20 which represent the words. It’s guaranteed that the words are distinct.
The third line contains n integers a1, a2, …, an (1 ≤ ai ≤ 109) where ai is the cost of sending the i-th word.
The next k lines describe the groups of words of same meaning. The next k lines each start with an integer x (1 ≤ x ≤ n) which means that there are x words in this group, followed by x integers which represent the indices of words in this group. It’s guaranteed that each word appears in exactly one group.
The next line contains m space-separated words which represent Mahmoud’s message. Each of these words appears in the list of language’s words.
Output
The only line should contain the minimum cost to send the message after replacing some words (maybe none) with some words of the same meaning.
Examples
input
5 4 4
i loser am the second
100 1 1 5 10
1 1
1 3
2 2 5
1 4
i am the second
output
107
input
5 4 4
i loser am the second
100 20 1 5 10
1 1
1 3
2 2 5
1 4
i am the second
output
116
Note
In the first sample, Mahmoud should replace the word “second” with the word “loser” because it has less cost so the cost will be 100+1+5+1=107.
In the second sample, Mahmoud shouldn’t do any replacement so the cost will be 100+1+5+10=116.
题意：
Mahmoud发送消息给好友，每个消息包含多个字符串，发送消息中的每个字符串需要花费一定的费用，但是其中有些字符串所表达的含义一样，可以互相替换，求发送消息的最小费用。
解题思路：
建立一个HashMap集合，将每个字符串作为键值，能互相交换的的字符串其键值对应的值为相同的发送价格值的下标，然后将字符串的价格存入在数组中，如果有可以替换的字符串，比较其价格，将花费最小的值存入数组中。因为HashMap的键值所对应的值就是其在花费的数组的下标。最后通过输入要发送字符串（即HashMap的键值）找到HashMap键值所对应值即花费数组的下表，将价格累加即可。
AC–Code
import java.util.Arrays;
import java.util.HashMap;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int k = sc.nextInt();
int m =sc.nextInt();
String[] s = new String[n];
for(int i=0 ;i<n;i++)
{
s[i] = sc.next();
}
int[] d = new int[n];
for(int i = 0;i<n;i++)
{
d[i] = sc.nextInt();
}
HashMap<String, Integer> map = new HashMap<String,Integer>();
int[] min = new int[k];
Arrays.fill(min,Integer.MAX_VALUE);
for(int i =0;i<k;i++)
{
int count = sc.nextInt();
while(count-->0)
{
int x = sc.nextInt()-1;
map.put(s[x],i);
min[i] = Math.min(min[i], d[x]);
}
}
long p = 0;
for(int i = 0;i<m;i++)
{
p+=min[map.get(sc.next())];
}
System.out.println(p);
sc.close();
}
}