Message Flood

来源:互联网 发布:u盘数据丢失 编辑:程序博客网 时间:2024/05/16 11:24

Message Flood

Time Limit: 1500ms   Memory limit: 65536K  有疑问?点这里^_^

题目描述

Well, how do you feel about mobile phone? Your answer would probably be something like that "It's so convenient and benefits people a lot". However, If you ask Merlin this question on the New Year's Eve, he will definitely answer "What a trouble! I have to keep my fingers moving on the phone the whole night, because I have so many greeting message to send!" Yes, Merlin has such a long name list of his friends, and he would like to send a greeting message to each of them. What's worse, Merlin has another long name list of senders that have sent message to him, and he doesn't want to send another message to bother them Merlin is so polite that he always replies each message he receives immediately). So, before he begins to send message, he needs to figure to how many friends are left to be sent. Please write a program to help him. Here is something that you should note. First, Merlin's friend list is not ordered, and each name is alphabetic strings and case insensitive. These names are guaranteed to be not duplicated. Second, some senders may send more than one message to Merlin, therefore the sender list may be duplicated. Third, Merlin is known by so many people, that's why some message senders are even not included in his friend list.

输入

There are multiple test cases. In each case, at the first line there are two numbers n and m (1<=n,m<=20000), which is the number of friends and the number of messages he has received. And then there are n lines of alphabetic strings(the length of each will be less than 10), indicating the names of Merlin's friends, one per line. After that there are m lines of alphabetic strings, which are the names of message senders. The input is terminated by n=0.

输出

For each case, print one integer in one line which indicates the number of left friends he must send.

示例输入

5 3InkfishHenryCarpMaxJerichoCarpMaxCarp0

示例输出

3

来源

第9届中山大学程序设计竞赛预选赛


这道题的大意是:输入n个到名字单1上(不重复),输入m个名字到名单2(可能重复),求出名单1中没有出现名单2名字的个数。(注意,大小写不区分)


这里,我先采用的简单匹配,很不幸,TLE。

#include<iostream>#include<string.h>using namespace std;int main(){    int n,m;    while(cin>>n)    {        if(n==0)            break;        cin>>m;        char st1[20010][10],st2[20010][10];        int a[20010];        for(int i=0; i<n; i++)        {            cin>>st1[i];            for(int j=0,len=strlen(st1[i]); j<len; j++)                st1[i][j]=tolower(st1[i][j]);       //c语言提供的转化小写的函数        }        for(int i=0; i<m; i++)        {            cin>>st2[i];            for(int j=0,len=strlen(st2[i]); j<len; j++)                st2[i][j]=tolower(st2[i][j]);            for(int j=0; j<n; j++)                if(strcmp(st1[j],st2[i])==0)                    a[j]=1;        }        int count=0;        for(int i=0; i<n; i++)            if(!a[i])                count++;        cout<<count<<endl;    }    return 0;}

然后自学了STL中的容器和迭代器抓狂,这里采用set容器解决。

#include<iostream>#include<set>#include<string>#include<algorithm>         //transfrom()的头文件using namespace std;int main(){    int n,m;    while(cin>>n&&n)    {        cin>>m;        set<string> List;        for(int i=0; i<n; i++)        {            string st;            cin>>st;            transform(st.begin(),st.end(),st.begin(),::tolower);//原字符串首,原字符串尾,新字符串首,操作            List.insert(st);        }        for(int i=0; i<m; i++)        {            string st;            cin>>st;            transform(st.begin(),st.end(),st.begin(),::tolower);            List.erase(st);        }        cout<<List.size()<<endl;    }    return 0;}



0 0
原创粉丝点击