Uva12412 师兄帮帮忙

#include<bits/stdc++.h>using namespace std;class Student{public:    string sid;    int cid,score1,score2,score3,score4,totalscore,rank;    string name;    Student(string sid,int cid,string name,int score1,int score2,int score3,int score4):sid(sid),cid(cid),score1(score1),score2(score2),score3(score3),score4(score4),name(name)    {    }    Student()    {    }//无参构造函数    friend istream& Operator >>(istream& in,Student& x)//重定向输入流    {        in>>x.cid>>x.name>>x.score1>>x.score2>>x.score3>>x.score4;        x.totalscore=x.score1+x.score2+x.score3+x.score4;        x.rank=0;        return in;    }    friend ostream& operator <<(ostream& out,Student& x)    {        out<<x.rank<<" "<<x.sid<<" "<<x.cid<<" "<<x.name<<" "<<x.score1<<" "<<x.score2<<" "<<x.score3<<" ";        out<<x.score4<<" "<<x.totalscore<<" ";        PRintf("%.2f/n",x.totalscore/4.0);        return out;    }};vector<Student> myvector;void paixu(void){    int rnk=1,cnt;    for(int i=400;i>=0;i--)    {        cnt=0;//cnt represents the number of students whose totalscore equals to i        for(auto &it:myvector)        {            if(it.totalscore==i)            {                it.rank=rnk;                cnt++;            }        }        rnk+=cnt;    }}void query(void){    paixu();//to calculate everyone's rank    double averagescore;    while(true)    {        printf("Please enter SID or name. Enter 0 to finish./n");        string input;        cin>>input;        if(input=="0")            break;        if(isdigit(input[0]))//the input is student id        {            for(auto &it:myvector)                if(it.sid==input)                {                    //printf("The rank of this student is %d/n",it.rank);                    cout<<it;                }        }        else        {            for(auto &it:myvector)                if(it.name==input)                    cout<<it;        }    }}void add(void){    while(true)    {        printf("Please enter the SID, CID, name and four scores. Enter 0 to finish./n");        Student temp;        string tempinput;        cin>>tempinput;        if(tempinput=="0")            break;        else        {            temp.sid=tempinput;            cin>>temp;        }        bool flag=false;        for(auto &it:myvector)            if(it.sid==temp.sid)                flag=true;        if(flag)            printf("Duplicated SID./n");        else            myvector.push_back(temp);    }}void remove(void){    while(true)    {        int cnt=0;        printf("Please enter SID or name. Enter 0 to finish./n");        vector<Student>::iterator it;        string input;        cin>>input;        if(input=="0")            break;        if(isdigit(input[0]))//the input is student id        {            for(it=myvector.begin();it!=myvector.end();)            {                if((*it).sid==input)                {                    cnt++;                    it=myvector.erase(it);                }                else                    it++;            }        }        else//the input is a name        {            for(it=myvector.begin();it!=myvector.end();)            {                if((*it).name==input)                {                    cnt++;                    it=myvector.erase(it);                }                else                    it++;            }        }        printf("%d student(s) removed./n",cnt);    }}void ranking(void){    printf("Showing the ranklist hurts students' self-esteem. Don't do that./n");}void statistics(void){    double average;    int num_passed,num_failed,id;    printf("Please enter class ID, 0 for the whole statistics./n");    cin>>id;    //创建一个新的vector用来进行数据统计    vector<Student>stat;    stat.clear();    if(id==0)    {        for(auto &it:myvector)            stat.push_back(it);    }    else    {        for(auto &it:myvector)        {            if(it.cid==id)                stat.push_back(it);        }    }    //对每一门学科进行统计    {        average=num_passed=num_failed=0;        for(auto &it:stat)        {            average+=it.score1;            if(it.score1>=60)                num_passed++;            else                num_failed++;        }        printf("Chinese/n");        if(stat.size()==0)            printf("Average Score: 0.00/n");        else            printf("Average Score: %.2f/n",average/stat.size());        printf("Number of passed students: %d/n",num_passed);        printf("Number of failed students: %d/n/n",num_failed);    }    {        average=num_passed=num_failed=0;        for(auto &it:stat)        {            average+=it.score2;            if(it.score2>=60)                num_passed++;            else                num_failed++;        }        printf("Mathematics/n");        if(stat.size()==0)            printf("Average Score: 0.00/n");        else            printf("Average Score: %.2f/n",average/stat.size());        printf("Number of passed students: %d/n",num_passed);        printf("Number of failed students: %d/n/n",num_failed);    }    {        average=num_passed=num_failed=0;        for(auto &it:stat)        {            average+=it.score3;            if(it.score3>=60)                num_passed++;            else                num_failed++;        }        printf("English/n");        if(stat.size()==0)            printf("Average Score: 0.00/n");        else            printf("Average Score: %.2f/n",average/stat.size());        printf("Number of passed students: %d/n",num_passed);        printf("Number of failed students: %d/n/n",num_failed);    }    {        average=num_passed=num_failed=0;        for(auto &it:stat)        {            average+=it.score4;            if(it.score4>=60)                num_passed++;            else                num_failed++;        }        printf("Programming/n");        if(stat.size()==0)            printf("Average Score: 0.00/n");        else            printf("Average Score: %.2f/n",average/stat.size());        printf("Number of passed students: %d/n",num_passed);        printf("Number of failed students: %d/n/n",num_failed);    }    int num_pass[5]={0,0,0,0,0};//num_pass[i] represents the number of students who pass no less than i courses    //exception:num_pass[0] represents the number of students who failed all the tests    for(auto &it:stat)    {        int cnt=0;//统计每个人过了几门课        if(it.score1>=60)            cnt++;        if(it.score2>=60)            cnt++;        if(it.score3>=60)            cnt++;        if(it.score4>=60)            cnt++;        for(int i=1;i<=4;i++)        {            if(cnt>=i)                num_pass[i]++;        }        if(cnt==0)            num_pass[0]++;    }    printf("Overall:/n");    printf("Number of students who passed all subjects: %d/n",num_pass[4]);    printf("Number of students who passed 3 or more subjects: %d/n",num_pass[3]);    printf("Number of students who passed 2 or more subjects: %d/n",num_pass[2]);    printf("Number of students who passed 1 or more subjects: %d/n",num_pass[1]);    printf("Number of students who failed all subjects: %d/n/n",num_pass[0]);}void menu(void)//主菜单{    int x;    bool flag=true;//控制何时退出    while(flag)    {        printf("Welcome to Student Performance Management System (SPMS)./n/n");        printf("1 - Add/n");        printf("2 - Remove/n");        printf("3 - Query/n");        printf("4 - Show ranking/n");        printf("5 - Show Statistics/n");        printf("0 - Exit/n/n");//watch out for this /n!!!        cin>>x;        switch(x)        {            case 1:add();                   break;            case 2:remove();                   break;            case 3:query();                   break;            case 4:ranking();                   break;            case 5:statistics();                   break;            case 0:flag=false;        }    }}int main(void){    //freopen("in.txt","r",stdin);    //freopen("out.txt","w",stdout);    myvector.clear();    menu();    return 0;}