UVA12412 A Typical Homework (a.k.a Shi Xiong Bang Bang Mang) 代码

#include <bits/stdc++.h>
#define int long long
#define judge(a,func) case a:func();break;
using namespace std;
void println(string s){
	cout<<s<<'\n';
}
void main_menu(){
	println("Welcome to Student Performance Management System (SPMS).");
	println("");
	println("1 - Add");
	println("2 - Remove");
	println("3 - Query");
	println("4 - Show ranking");
	println("5 - Show Statistics");
	println("0 - Exit");
	println("");
}
struct Student{
	string sid,name;
	int cid;
	int chinese,mathematics,english,programming;
	bool operator==(const Student &x) const{
		return sid==x.sid && cid==x.cid && chinese==x.chinese && mathematics==x.mathematics && english==x.english && programming == x.programming;
	}
};
vector<Student> v;
map<string,bool> duplicated;
void add(){
	println("Please enter the SID, CID, name and four scores. Enter 0 to finish.");
	string sid;
	cin>>sid;
	if(sid=="0")return;
	Student student;
	student.sid=sid;
	cin>>student.cid>>student.name>>student.chinese>>student.mathematics>>student.english>>student.programming;
	if(duplicated[sid]){
		println("Duplicated SID.");
	}
	else{
		duplicated[sid]=1;
		v.push_back(student);
	}
	add();
}
void remove(){
	println("Please enter SID or name. Enter 0 to finish.");
	string str;
	cin>>str;
	stack<vector<Student>::iterator> removing;
	if(str=="0")return;
	int tot=0;
	for(auto ite=v.begin();ite!=v.end();ite++){
		if((*ite).sid==str || (*ite).name==str){
			tot++;
			duplicated[(*ite).sid]=0;
			removing.push(ite);
		}
	}
	while(!removing.empty()){
		v.erase(removing.top());
		removing.pop();
	}
	cout<<tot;
	println(" student(s) removed.");
	remove();
}
int total(Student x){
	return x.chinese+x.english+x.mathematics+x.programming;
}
void query(){
	println("Please enter SID or name. Enter 0 to finish.");
	string str;
	cin>>str;
	if(str=="0")return;
	for(Student i : v){
		if(i.sid==str || i.name==str){
			vector<Student> same_class;
			for(Student j : v){
				same_class.push_back(j);
			}
			sort(same_class.begin(),same_class.end(),[&](const Student &x,const Student &y){
				return x.chinese+x.mathematics+x.english+x.programming>y.chinese+y.mathematics+y.english+y.programming;
			});
			int ret=0;
			for(vector<Student>::size_type j=0;j<same_class.size();j++){
				if(j>0&&total(same_class[j])==total(same_class[j-1])){}
				else ret=j+1;
				if(same_class[j]==i){
					break;
				}
			}
			cout<<ret<<' '<<i.sid<<' '<<i.cid<<' '<<i.name<<' ';
			cout<<i.chinese<<' '<<i.mathematics<<' '<<i.english<<' '<<i.programming<<' ';
			cout<<(i.chinese+i.mathematics+i.english+i.programming)<<' ';
			printf("%.2lf\n",((double)((i.chinese+i.mathematics+i.english+i.programming))/4.0)+1e-5);
		}
	}
	query();
}
void show_ranking(){
	println("Showing the ranklist hurts students' self-esteem. Don't do that.");
}
void show_statisitics(){
	println("Please enter class ID, 0 for the whole statistics.");
	int cid;cin>>cid;
	int passed=0,failed=0;
	double aver=0;
	int cnt=0;
	for(Student i : v){
		if(i.cid!=cid&&cid!=0)continue;
		cnt++;
	}
	{
		println("Chinese");
		for(Student i : v){
			if(i.cid!=cid&&cid!=0)continue;
			aver += i.chinese;
			passed += (i.chinese >= 60);
			failed += (i.chinese < 60);
		}
		aver /= cnt;
		cout<<"Average Score: ";
		printf("%.2lf\n",aver+1e-5);
		cout<<"Number of passed students: "<<passed<<'\n';
		cout<<"Number of failed students: "<<failed<<'\n';
		println("");
	}
	{
		aver=0;failed=0;passed=0;
		println("Mathematics");
		for(Student i : v){
			if(i.cid!=cid&&cid!=0)continue;
			aver += i.mathematics;
			passed += (i.mathematics >= 60);
			failed += (i.mathematics < 60);
		}
		aver /= cnt;
		cout<<"Average Score: ";
		printf("%.2lf\n",aver+1e-5);
		cout<<"Number of passed students: "<<passed<<'\n';
		cout<<"Number of failed students: "<<failed<<'\n';
		println("");
	}
	{
		aver=0;failed=0;passed=0;
		println("English");
		for(Student i : v){
			if(i.cid!=cid&&cid!=0)continue;
			aver += i.english;
			passed += (i.english >= 60);
			failed += (i.english < 60);
		}
		aver /= cnt;
		cout<<"Average Score: ";
		printf("%.2lf\n",aver+1e-5);
		cout<<"Number of passed students: "<<passed<<'\n';
		cout<<"Number of failed students: "<<failed<<'\n';
		println("");
	}
	{
		aver=0;failed=0;passed=0;
		println("Programming");
		for(Student i : v){
			if(i.cid!=cid&&cid!=0)continue;
			aver += i.programming;
			passed += (i.programming >= 60);
			failed += (i.programming < 60);
		}
		aver /= cnt;
		cout<<"Average Score: ";
		printf("%.2lf\n",aver+1e-5);
		cout<<"Number of passed students: "<<passed<<'\n';
		cout<<"Number of failed students: "<<failed<<'\n';
		println("");
	}
	println("Overall:");
	int all=0,one=0,two=0,three=0,failed_all=0;
	for(Student i : v){
		if(i.cid!=cid&&cid!=0)continue;
		int ret = (int)(i.chinese>=60)+(int)(i.mathematics>=60)+(int)(i.english>=60)+(int)(i.programming>=60);
		if(ret>=1)one++;
		if(ret>=2)two++;
		if(ret>=3)three++;
		if(ret>=4)all++;
		if(ret==0)failed_all++;
	}
	cout<<"Number of students who passed all subjects: "<<all<<'\n';
	cout<<"Number of students who passed 3 or more subjects: "<<three<<'\n';
	cout<<"Number of students who passed 2 or more subjects: "<<two<<'\n';
	cout<<"Number of students who passed 1 or more subjects: "<<one<<'\n';
	cout<<"Number of students who failed all subjects: "<<failed_all<<'\n';
	println("");
}
signed main(){
// freopen("1.out","w",stdout);
	while(1){
		main_menu();
		int op;
		cin>>op;
		switch(op){
			judge(1,add);
			judge(2,remove);
			judge(3,query);
			judge(4,show_ranking);
			judge(5,show_statisitics);
			case 0:return 0;
		}
	}
}