c++ set容器排序准则

转载两篇博客：

http://blog.csdn.net/lishuhuakai/article/details/51404214

http://blog.csdn.net/lihao21/article/details/6302196/

以下是实验代码：

#include <iostream>
#include <set>
#include<algorithm>
using namespace std;  

    /*Student结构体*/
    struct Student {
    string name;
    int id;
    int score;
    };  

        /*“仿函数"。为Student set指定排序准则*/
        class studentSortCriterion {
        public:  
　　　　　　　/*类型要与set容器类型一致*/
            bool operator() (const Student *a, const Student *b) const {
                return (a->id == b->id) ? (a->score > b->score) :(a->id > b->id);
            }
        };  

int main()
{
    set<Student*, studentSortCriterion> stuSet;
    set<Student*> stus;

    Student stu1, stu2,stu3;
    stu1.name = "张三";
    stu1.id =;
    stu1.score = ;  

    stu2.name = "李四";
    stu2.id = ;
    stu2.score = ;  

    stu3.name = "小明";
    stu3.id = ;
    stu3.score = ;

    stuSet.insert(&stu1);
    stuSet.insert(&stu2);
    stuSet.insert(&stu3);   

    Student stuTem;
    stuTem.score = ;
    stuTem.id = ;
    Student* stuTempPtr;
    set<Student*, studentSortCriterion>::iterator iter;
    iter = stuSet.find(&stuTem);
    if(iter != stuSet.end()) {
    　　cout << (*iter)->name << endl;
    }
　　 else {
    　　cout << "Cannot find the student!" << endl;
    }  

    for(std::set<Student*,studentSortCriterion>::iterator it = stuSet.begin();it!=stuSet.end();it++ ){
        std::cout<<(*it)->name<<endl;
    }
}  

上面程序会根据学生ID先进行排名然后再根据分数进行排名，排序准则需要满足以下要求，摘自C++标准库第二版：

输出结果：

小明
小明
张三
李四