【例题4-6 uva12412】A Typical Homework (a.k.a Shi Xiong Bang Bang Mang)

【链接】 我是链接,点我呀:)

【题意】

在这里输入题意

【题解】

训练编程的题。
原题中没有除0的数据,所以别担心你的代码是因为除0错了。
多半跟我一样。
也是因为没有+eps
就是比如你要算tot/4的值。
那么要输出tot/4+1e-6
不然会错。。。
浮点误差...

剩下的。其实很简答的。。

注意有并列第x的情况就好。

【代码】

#include <bits/stdc++.h>
using namespace std;

const string subject[4]={"Chinese","Mathematics","English","Programming"};

struct abc{
    string sid,cid,name;
    int goal[4];int tot;
};

int ope;
vector<abc> v;
vector<abc> temp;
map<string,int> ranking;

void output_message(){
    cout<<"Welcome to Student Performance Management System (SPMS)."<<endl<<endl;
    cout<<"1 - Add"<<endl;
    cout<<"2 - Remove"<<endl;
    cout<<"3 - Query"<<endl;
    cout<<"4 - Show ranking"<<endl;
    cout<<"5 - Show Statistics"<<endl;
    cout<<"0 - Exit"<<endl<<endl;
}

void tip(int idx){
    if (idx==1) cout<<"Please enter the SID, CID, name and four scores. Enter 0 to finish."<<endl;
    if (idx==2) cout<<"Please enter SID or name. Enter 0 to finish."<<endl;
    if (idx==3) cout<<"Please enter SID or name. Enter 0 to finish."<<endl;
    if (idx==4) cout<<"Showing the ranklist hurts students' self-esteem. Don't do that."<<endl;
    if (idx==5) cout<<"Please enter class ID, 0 for the whole statistics."<<endl;
}

bool found_student_by_sid(string sid){
    for (abc temp:v) if (temp.sid==sid) return true;
    return false;
}

int _remove(string par,int p){
    int cnt = 0;
    vector<abc> newv;newv.clear();
    for (int i = 0;i < (int) v.size();i++){
        if ( (p==0 && v[i].sid == par) || (p==1 && v[i].name == par)  ){
            cnt++;
        }else newv.push_back(v[i]);
    }
    v.resize((int)newv.size());
    v = newv;
    return cnt;
}

bool cmp(abc a,abc b){
    return a.tot>b.tot;
}

int main(){
    //freopen("/home/ccy/rush.txt","r",stdin);
    //freopen("/home/ccy/rush_out.txt","w",stdout);
    ios::sync_with_stdio(0),cin.tie(0);
    while (1){
        output_message();
        cin >> ope;
        if (ope==1){
            while(1){
                tip(1);
                abc temp;
                cin >> temp.sid;
                if (temp.sid=="0") break;
                temp.tot = 0;
                cin >> temp.cid >> temp.name;
                for (int i = 0;i < 4;i++){
                    cin >> temp.goal[i];
                    temp.tot+=temp.goal[i];
                }
                if (found_student_by_sid(temp.sid))
                    cout<<"Duplicated SID."<<endl;
                else
                    v.push_back(temp);
            }
        }
        if (ope==2){
            while (1){
                tip(2);
                string s;
                cin >> s;
                if (s=="0") break;
                int p = 0;
                if (s[0]>='A' && s[0]<='Z') p = 1;
                cout<<_remove(s,p)<<" student(s) removed."<<endl;
            }
        }
        if (ope==3){
            while (1){
                tip(3);
                string s;
                cin >> s;
                if (s=="0") break;
                temp.resize((int)v.size());
                for (int i = 0;i < (int)v.size();i++) temp[i] = v[i];
                sort(temp.begin(),temp.end(),cmp);
                for (int i = 0;i < (int)v.size();i++){
                    int cur = i+1,j = i;
                    ranking[temp[i].sid] = cur;
                    while (j+1<(int)v.size() && temp[j+1].tot==temp[i].tot) {
                        j++;
                        ranking[temp[j].sid] = cur;
                    }
                    i = j;
                }
                int p = 0;
                if (s[0]>='A' && s[0]<='z') p = 1;
                for (int i = 0;i < (int)v.size();i++){
                    if ( (p==0 && v[i].sid == s) || (p==1 && v[i].name==s) ){
                        cout<<ranking[v[i].sid]<<" ";
                        cout<<v[i].sid<<" "<<v[i].cid<<" "<<v[i].name<<" ";
                        for (int j = 0;j < 4;j++) cout<<v[i].goal[j]<<" ";
                        cout<<v[i].tot<<" ";
                        cout<<fixed<<setprecision(2)<<1.0*v[i].tot/4.0+(1e-5)<<endl;
                    }
                }
            }
        }
        if (ope==4) tip(4);
        if (ope==5){
            tip(5);
            string s;
            cin >> s;
            for (int i = 0;i < 4;i++){
                int cntb60 = 0,cntl60 = 0,tot =0,cnt = 0;
                for (int j = 0;j < (int)v.size();j++){
                    if (v[j].cid==s || s=="0"){
                        if (v[j].goal[i]>=60){
                            cntb60++;
                        }else cntl60++;
                        tot+=v[j].goal[i];
                        cnt++;
                    }
                }
                cout<<subject[i]<<endl;
                cout<<"Average Score: ";
                cout<<fixed<<setprecision(2)<<1.0*tot/(1.0*cnt)+(1e-5)<<endl;

                cout<<"Number of passed students: "<<cntb60<<endl;
                cout<<"Number of failed students: "<<cntl60<<endl;
                cout<<endl;
            }
           cout<<"Overall:"<<endl;
           int cnt[5]={0};
           for (int i = 0;i < (int)v.size();i++)
               if (v[i].cid==s || s=="0"){
                  int temp = 0;
                  for (int j = 0;j < 4;j++){
                    if (v[i].goal[j]>=60) temp++;
                  }
                  cnt[temp]++;
               }
           cout<<"Number of students who passed all subjects: "<<cnt[4]<<endl;
           for (int i = 3;i >= 1;i--) cnt[i]+=cnt[i+1];
           for (int i = 3;i >= 1;i--)
                cout<<"Number of students who passed "<<i<<" or more subjects: "<<cnt[i]<<endl;
           cout<<"Number of students who failed all subjects: "<<cnt[0]<<endl;
           cout<<endl;
        }

        if (ope==0){
            break;
        }
    }
    return 0;
}