If you’ve seen television commercials for long-distance phone companies lately, you’ve noticed thatmany companies have been spending a lot of money trying to convince people that they provide thebest service at the lowest cost. One company has “calling circles.” You provide a list of people thatyou call most frequently. If you call someone in your calling circle (who is also a customer of the samecompany), you get bigger discounts than if you call outside your circle. Another company points outthat you only get the big discounts for people in your calling circle, and if you change who you callmost frequently, it’s up to you to add them to your calling circle.
LibertyBell Phone Co. is a new company that thinks they have the calling plan that can put othercompanies out of business. LibertyBell has calling circles, but they figure out your calling circle foryou. This is how it works. LibertyBell keeps track of all phone calls. In addition to yourself, yourcalling circle consists of all people whom you call and who call you, either directly or indirectly.
For example, if Ben calls Alexander, Alexander calls Dolly, and Dolly calls Ben, they are all withinthe same circle. If Dolly also calls Benedict and Benedict calls Dolly, then Benedict is in the samecalling circle as Dolly, Ben, and Alexander. Finally, if Alexander calls Aaron but Aaron doesn’t callAlexander, Ben, Dolly, or Benedict, then Aaron is not in the circle.
You’ve been hired by LibertyBell to write the program to determine calling circles given a log ofphone calls between people.
Input
The input file will contain one or more data sets. Each data set begins with a line containing twointegers, n and m. The first integer, n, represents the number of different people who are in the dataset. The maximum value for n is 25. The remainder of the data set consists of m lines, each representinga phone call. Each call is represented by two names, separated by a single space. Names are first namesonly (unique within a data set), are case sensitive, and consist of only alphabetic characters; no nameis longer than 25 letters.
For example, if Ben called Dolly, it would be represented in the data file as
Ben DollyInput
is terminated by values of zero (0) for n and m.
Output
For each input set, print a header line with the data set number, followed by a line for each callingcircle in that data set. Each calling circle line contains the names of all the people in any order withinthe circle, separated by comma-space (a comma followed by a space). Output sets are separated byblank lines.
原题链接：点击打开链接
数据量很小，直接套floyd的三重循环，让可以相互沟通的节点连在一起，让后暴力枚举一遍。还是比较简单AC的
#include <iostream>
#include <map>
#include <string>
#include <cstring>
using namespace std;
int m,n,Time=1,pd[30][30],f[30];
string s[30];
int main()
{
while(cin>>n>>m)
{
if(n==0&&m==0)break;
int cnt=0;
memset(pd,0,sizeof(pd));
memset(f,0,sizeof(f));
map<string,int>p;
for(int i=1;i<=m;i++)
{
string s1,s2;
cin>>s1>>s2;
if(!p.count(s1)) p[s1]=cnt++;
if(!p.count(s2)) p[s2]=cnt++;
int x1=p[s1],x2=p[s2]; //把字符串用数字标记，便于后面的使用
//cout<<x1<<x2<<endl;
s[x1]=s1,s[x2]=s2;//cout<<1<<endl;
pd[x1][x2]=1;
}
for(int k=0;k<n;k++) //以下是Floyd算法
for(int i=0;i<n;i++)
for(int j=0;j<n;j++)
{
if(pd[i][k]==1&&pd[k][j]==1) pd[i][j]=1; //把相互可以连通的点连通
}
cout<<"Calling circles for data set "<<Time<<":"<<endl;
Time++;
for(int i=0;i<n;i++)
{
if(f[i]==1)continue; //避免同一个电话环变着顺序的输出
cout<<s[i];
for(int j=0;j<n;j++)
{
if(i==j)continue;
if(pd[i][j]!=1||pd[j][i]!=1)continue;
cout<<", "<<s[j]; //逗号后面有个空格，之前没有注意然后WA了一遍，很难受
f[j]=1; //标记他已经输出过了
}
cout<<endl;
}
}
return 0;
}