CF 5A Chat Server's Outgoing Traffic(字符串模拟)

Chat Server's Outgoing Traffic

Time Limit: 1000ms

Memory Limit: 65536KB
This problem will be judged on CodeForces.
Original ID: 5A

64-bit integer IO format: %I64d
Java class name: (Any)

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Tag it!

Polycarp is working on a new project called "Polychat". Following modern tendencies in IT, he decided, that this project should contain chat as well. To achieve this goal, Polycarp has spent several hours in front
of his laptop and implemented a chat server that can process three types of commands:

Include a person to the chat ('Add' command).
Remove a person from the chat ('Remove' command).
Send a message from a person to all people, who are currently in the chat, including the one, who sends the message ('Send' command).

Now Polycarp wants to find out the amount of outgoing traffic that the server will produce while processing a particular set of commands.
Polycarp knows that chat server sends no traffic for 'Add' and 'Remove' commands. When 'Send' command is processed, server sends l bytes
to each participant of the chat, where l is the length of the message.
As Polycarp has no time, he is asking for your help in solving this problem.

Input

Input file will contain not more than 100 commands, each in its own line. No line will exceed 100 characters. Formats of the commands will be the following:

+<name> for 'Add' command.
-<name> for 'Remove' command.
<sender_name>:<message_text> for 'Send' command.

<name> and <sender_name> is
a non-empty sequence of Latin letters and digits. <message_text> can contain letters, digits and spaces, but can't start or end with a space. <message_text> can
be an empty line.
It is guaranteed, that input data are correct, i.e. there will be no 'Add' command if person with such a name is
already in the chat, there will be no 'Remove'command if there is no person with such a name in the chat etc.
All names are case-sensitive.

Output

Print a single number — answer to the problem.

Sample Input

Input

+Mike
Mike:hello
+Kate
+Dmitry
-Dmitry
Kate:hi
-Kate

Output

9

Input

+Mike
-Mike
+Mike
Mike:Hi   I am here
-Mike
+Kate
-Kate

Output

14

Source

Codeforces Beta Round #5

题意:

一个聊天服务器,"+"+人名表示该人加入聊天,"-"+人名表示该退出入聊天,人名后面冒号后面的内容表示该人发的消息,一个人发的消息当前聊天的人都可以接受到,问一共接收到多少个字符.

简单模拟,注意:发的消息在冒号后面,

AC代码:

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int main()
{
char a[100];
int sum=0;
int ans=0;
while(gets(a))
{
int len=strlen(a);
if(a[0]=='+')
sum++;
else if(a[0]=='-')
sum--;
else
{
int p=0;
for(int i=0;i<len;i++)
if(a[i]==':')
p=i;
ans+=(len-p-1)*sum;
}
}
cout<<ans<<endl;
return 0;
}