pta 习题集5-18 打印学生选课清单

10 5
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
ZOE1 ANN0 BOB5 JOE4 JAY9 FRA8 DON2 AMY7 KAT3 LOR6

ZOE1 2 4 5
ANN0 3 1 2 5
BOB5 5 1 2 3 4 5
JOE4 1 2
JAY9 4 1 2 4 5
FRA8 3 2 4 5
DON2 2 4 5
AMY7 1 5
KAT3 3 2 4 5
LOR6 4 1 2 4 5

用cin会超时

用Hash ,由于只要3个大写字母和一个数字，就不要用map了

#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string>
#include <map>
#include <algorithm>
#include <vector>

using namespace std;
int n,k;
map<string,int> m;
char s[10];
vector<int> a[200005];
int fun(string s)
{
    return ((s[0]-'A')*26*26+(s[1]-'A')*26+(s[2]-'A'))*10+s[3]-'0';
}
int main()
{
    scanf("%d%d",&n,&k);
    int x;
    int cnt=0;
    int y;
    for(int i=1;i<=k;i++)
    {
        scanf("%d",&y);
        scanf("%d",&x);
        
        for(int j=1;j<=x;j++)
        {
            scanf("%s",s);
            a[fun(s)].push_back(y);
        }
    }
    for(int i=1;i<=n;i++)
    {
        scanf("%s",s);
        printf("%s",s);
        int x=fun(s);
        int len=a[x].size();
        printf(" %d",len);
        
        sort(a[x].begin(),a[x].end());
        
        
        for(int i=0;i<len;i++)
        {
            printf(" %d",a[x][i]);
           
        }
        printf("\n");
    }
    return 0;
    
}