1083 List Grades(set,运算符重载)

1083 List Grades （25 分）

Given a list of N student records with name, ID and grade. You are supposed to sort the records with respect to the grade in non-increasing order, and output those student records of which the grades are in a given interval.

Input Specification:

Each input file contains one test case. Each case is given in the following format:
N
name[1] ID[1] grade[1]
name[2] ID[2] grade[2]
... ...
name[N] ID[N] grade[N]
grade1 grade2
where name[i] and ID[i] are strings of no more than 10 characters with no space, grade[i] is an integer in [0, 100], grade1 and grade2 are the boundaries of the grade's interval. It is guaranteed that all the grades are distinct.

Output Specification:

For each test case you should output the student records of which the grades are in the given interval [grade1, grade2] and are in non-increasing order. Each student record occupies a line with the student's name and ID, separated by one space. If there is no student's grade in that interval, output NONE instead.

Sample Input 1:

4
Tom CS000001 59
Joe Math990112 89
Mike CS991301 100
Mary EE990830 95
60 100

Sample Output 1:

Mike CS991301
Mary EE990830
Joe Math990112
Sample Input 2:
2
Jean AA980920 60
Ann CS01 80
90 95

分析

本题本质上在考察结构体的排序，但是set在生成的过程是有序的，因此，我们只需重载>运算符，并且在定义set时指定是按照less排序还是按照greater排序。

#include <iostream>
#include <set>
using namespace std;
struct node {
    string name,id;
    int score;
};
bool operator>(const node &a,const node &b) {
    return a.score>b.score;
}
set<node,greater<node> >s;
int main() {
    int n,g1,g2;
    cin>>n;
    for(int i=0; i<n; i++) {
        string name,id;
        int score;
        cin>>name>>id>>score;
        s.insert(node {name,id,score});
    }
    cin>>g1>>g2;
    bool flag=false;
    for (auto t : s) {
        if(g1<=t.score && t.score<=g2) {
            cout<<t.name<<" "<<t.id<<endl;
            flag=true;
        }
    }
    if(!flag) cout<<"NONE"<<endl;
    return 0;
}