【PAT】1047. Student List for Course (25)
题目链接： http://pat.zju.edu.cn/contests/pat-a-practise/1047
题目描述：
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.
Input Specification:
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.
Output Specification:
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.
Sample Input: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 5Sample Output:
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
分析：
使用什么样的容器进行存储是关键。
参考：http://blog.csdn.net/sunbaigui/article/details/8656971
参考代码：
#include<iostream>
#include<vector>
#include<string.h>
#include<cstdio>
#include<functional>
#include<algorithm>
using namespace std;
typedef struct Node
{
char name[20];
bool operator < (const Node & n)const
{
return strcmp(name,n.name)<0;
}
}Node;
vector<Node> node;
bool cmp(int t1,int t2)
{
return strcmp(node[t1].name, node[t2].name)<0;
}
int main()
{
int N,K;
scanf("%d%d",&N,&K);
vector< vector<int> > result(K);
node.resize(N); //重新分配大小，注意这一句的写法。
int i;
int j;
for(i=0; i<N; i++)
{
int num;
int t;
scanf("%s %d",&node[i].name,&num);
for(j=0; j<num; j++)
{
scanf("%d",&t);
result[t-1].push_back(i); //t代表课程号,i代表学生编号
}
}
for(i=0; i<K; i++)
{
printf("%d %d\n",i+1, result[i].size());
sort(result[i].begin(),result[i].end(),cmp);
for(j=0; j<result[i].size(); j++)
{
printf("%s\n",node[ result[i][j] ].name);
}
}
return 0;
}
解法二：
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <queue>
#include <string.h>
using namespace std;
int N,K;
struct node{
char name[4];
bool operator > (const node & b) const{
return strcmp(name, b.name)>0;
}
};
struct cour{
priority_queue<node, vector<node>, greater<node> > stu;
};
int main(int argc, char** argv) {
scanf("%d%d",&N,&K);
int i, num, c;
char name[4];
vector< cour > cours(K+1);
for(i=0; i<N; i++){
node tmp;
scanf("%s %d",&tmp.name,&num);
for(int j=0; j<num; j++){
scanf("%d",&c);
cours[c].stu.push(tmp);
}
}
for(i=1; i<=K; i++){
int len = cours[i].stu.size();
printf("%d %d\n",i,len);
while(!cours[i].stu.empty()){
node tmp = cours[i].stu.top();
printf("%s\n",tmp.name);
//printf("%s\n",cours[i].stu.top().name); 不知道为什么用这一句输出会有问题？？？
cours[i].stu.pop();
}
}
return 0;
}