題目描述
Zhejiang University has 40000 students and provides 2500 courses. Now given the registered course list of each student, you are supposed to output the student name lists of all the courses.
輸入
Each input file contains one test case. For each case, the first line contains 2 numbers: N (<=40000), the total number of students, and K (<=2500), the total number of courses. Then N lines follow, each contains a student's name (3 capital English letters plus a one-digit number), a positive number C (<=20) which is the number of courses that this student has registered, and then followed by C course numbers. For the sake of simplicity, the courses are numbered from 1 to K.
輸出
For each test case, print the student name lists of all the courses in increasing order of the course numbers. For each course, first print in one line the course number and the number of registered students, separated by a space. Then output the students' names in alphabetical order. Each name occupies a line.
樣例輸入
10 5 ZOE1 2 4 5 ANN0 3 5 2 1 BOB5 5 3 4 2 1 5 JOE4 1 2 JAY9 4 1 2 5 4 FRA8 3 4 2 5 DON2 2 4 5 AMY7 1 5 KAT3 3 5 4 2 LOR6 4 2 4 1 5
樣例輸出
1 4 ANN0 BOB5 JAY9 LOR6 2 7 ANN0 BOB5 FRA8 JAY9 JOE4 KAT3 LOR6 3 1 BOB5 4 7 BOB5 DON2 FRA8 JAY9 KAT3 LOR6 ZOE1 5 9 AMY7 ANN0 BOB5 DON2 FRA8 JAY9 KAT3 LOR6 ZOE1
思路：和問題A一樣，比問題A還簡單一點，以課程代碼爲下標，數組存放學生姓名
#include<bits/stdc++.h>
using namespace std;
#define maxm 25000
vector<string> a[maxm];
int main()
{
int n,k;
int snum,knum;
string name;
cin>>n>>k;
for(int i=0;i<n;i++)
{
cin>>name>>snum;
for(int j=0;j<snum;j++)
{
cin>>knum;
a[knum].push_back(name);
}
}
vector<string>::iterator it;
for(int i=1;i<=k;i++)
{
cout<<i<<' '<<a[i].size();
sort(a[i].begin(),a[i].end());
for(it=a[i].begin();it!=a[i].end();it++)
cout<<endl<<*it;
cout<<endl;
}
return 0;
}