C++ STL vector A1039 Course List for Student

#include <bits/stdc++.h>
#include<math.h>
#include <string>
using namespace std;
const int N = 40005;
//vector<vector<int>>
const int M = 26*26*26*10 +1;//由姓名散列成的数字上界 
vector<int> selectCourse[M];//每个学生选择的课程编号
int getID(char name[]){
    int id = 0;
    for(int i=0;i<3;++i){
        id = id * 26 + (name[i] - ‘A‘);
    }
    id = id * 10 + (name[3] - ‘0‘);
    return id;
}
int main(){
    char name[5];
    int n,k;
    scanf("%d%d",&n,&k);
    for(int i=0;i<k;++i){
        int course,x;
        scanf("%d%d",&course,&x);
        for(int j=0;j<x;++j){
            scanf("%s",name);
            int id = getID(name);
            selectCourse[id].push_back(course);
        }
    }
    for(int i =0;i<n;++i){
        scanf("%s",name);
        int id = getID(name);
        sort(selectCourse[id].begin(),selectCourse[id].end());//从小到大排序
        printf("%s %d",name,selectCourse[id].size());//姓名，选课数
        for(int j=0;j<selectCourse[id].size();++j){
            printf(" %d",selectCourse[id][j]);
        }
        printf("\n");
    }
    system("pause");
    return 0;
}