题解 | #EXCEL排序#

#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
struct Student{
    string id;
    string name;
    int grade;
};
Student student[100000+1];
bool cmp1(Student a,Student b){
    return a.id<b.id;
}
bool cmp2(Student a,Student b){
    if (a.name!=b.name){//名字不相等按名字非降序输出
        return a.name<b.name;
    }
    else{//名字相等即按学号
        return a.id<b.id;
    }
}
bool cmp3(Student a,Student b){
    if (a.grade!=b.grade){//成绩不相等按名字非降序输出
        return a.grade<b.grade;
    }
    else{//成绩相等即按学号
        return a.id<b.id;
    }
}
int main(){
    int N,Case;
    while (cin>>N>>Case){
        if (N==0) break;
        for (int i = 0; i < N; ++i) {
            cin>>student[i].id>>student[i].name>>student[i].grade;
        }
        if (Case==1){
            sort(student,student+N, cmp1);
        }
        else if (Case==2){
            sort(student,student+N, cmp2);
        }
        else{
            sort(student,student+N, cmp3);
        }
        cout<<"Case:"<<endl;
        for (int i = 0; i < N; ++i) {
           cout<<student[i].id<<" "<<student[i].name<<" "<<student[i].grade<<endl;
        }
    }
}