牛客网考研复试题-成绩排序

题目地址：https://www.nowcoder.com/practice/0383714a1bb749499050d2e0610418b1?tpId=40&tqId=21333&tPage=1&rp=1&ru=/ta/kaoyan&qru=/ta/kaoyan/question-ranking

题解：结构体cmp排序，但是要注意是稳定排序，加一个index的标记

#include<iostream>
#include<stdio.h>
#include<algorithm>
using namespace std;

struct student{
    char name[20];
    int grade;
    int index;
};
struct student stu[55];
int  cmp1(struct student a,struct student b){//升序
    if(a.grade==b.grade){
        return a.index<b.index;
    }else{
        return a.grade<b.grade;
    }

}
int  cmp2(struct student a,struct student b){//降序
    if(a.grade==b.grade){
            return a.index<b.index;
        }else{
            return a.grade>b.grade;
    }
}
int main(){
    int flag,num;
    while(scanf("%d %d",&num,&flag)!=EOF){
        for(int i=0;i<num;i++){
            scanf("%s %d",stu[i].name,&stu[i].grade);
            stu[i].index=i;
        }
        if(flag==1){
            sort(stu,stu+num,cmp1);
            for(int  i=0;i<num;i++){
                printf("%s %d\n",stu[i].name,stu[i].grade);
            }
        }else{
            sort(stu,stu+num,cmp2);
            for(int  i=0;i<num;i++){
                printf("%s %d\n",stu[i].name,stu[i].grade);
            }
        }
    }
    return 0;
}