代码：
# include<stdio.h> # include<string> # include<iostream> # include<algorithm> using namespace std; struct student{ string id ,name; int grade; }stu[100010]; bool cmp1(student a,student b){ return a.id<b.id; } bool cmp2(student a,student b){ if(a.name!=b.name) return a.name<b.name; else return a.id<b.id; } bool cmp3(student a,student b){ if(a.grade!=b.grade) return a.grade<b.grade; else return a.id<b.id; } int main(){ int n,tag; cin>>n>>tag; for(int i=0;i<n;i++){ cin>>stu[i].id>>stu[i].name>>stu[i].grade; } if(tag==1)sort(stu,stu+n,cmp1); if(tag==2)sort(stu,stu+n,cmp2); if(tag==3)sort(stu,stu+n,cmp3); for(int i=0;i<n;i++) cout<<stu[i].id<<' '<<stu[i].name<<' '<<stu[i].grade<<'\n'; return 0; }