rt，孩纸调了 $5.5$ 个小时了，球球哪位 dalao 救救孩纸吧 $\dots$

#include <bits/stdc++.h>
#define ll long long
#define isremove(x) stu[x].IsRemove
using namespace std;
const double eps = 1e-5;
struct student{
	string name, sid;
	ll cid, c, m, e, p, total;
	bool IsRemove;
	double average;
}stu[1000010];
ll op, now, cnt, score[1000010];
map<string, bool> visit;
map<string, vector<ll> > pos1; // name
map<string, vector<ll> > pos2; // sid
void print(ll qwq){
	cout << stu[qwq].name << " " << stu[qwq].sid << endl;
	printf("%lld %lld %lld %lld %lld %lld\n", stu[qwq].cid, stu[qwq].c, stu[qwq].m, stu[qwq].e, stu[qwq].p, stu[qwq].total);
	cout << stu[qwq].IsRemove << endl;
	printf("%.2lf\n", stu[qwq].average + eps);
}
void welcome(){
	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");
}
void Add(){
	string s, name;
	ll CID, chi, math, eng, pro;
	while(1){
		printf("Please enter the SID, CID, name and four scores. Enter 0 to finish.\n");
		cin >> s;
		if(s == "0") break;
		cin >> CID >> name >> chi >> math >> eng >> pro;
		if(visit[s]){printf("Duplicated SID.\n"); continue;}
		stu[++now].name = name;
		stu[now].sid = s;
		stu[now].cid = CID;
		stu[now].c = chi; stu[now].m = math; stu[now].e = eng; stu[now].p = pro;
		stu[now].total = chi + math + eng + pro;
		stu[now].IsRemove = 0;
		stu[now].average = stu[now].total / 4.0;
		pos1[name].emplace_back(now);
		pos2[s].emplace_back(now);
		visit[s] = 1;
	}
}
void Remove(){
	string s;
	while(1){
		printf("Please enter SID or name. Enter 0 to finish.\n");
		cin >> s;
		if(s == "0") break;
		if(isdigit(s[0])){
			printf("%lld student(s) removed.\n", pos1[s].size());
			for(auto pos : pos1[s])
				stu[pos].IsRemove = 1;
		}else{
			printf("%lld student(s) removed.\n", pos2[s].size());
			for(auto pos : pos2[s])
				stu[pos].IsRemove = 1;
		}
	}
}
void Query(){
	string s;
	while(1){
		printf("Please enter SID or name. Enter 0 to finish.\n");
		cin >> s;
		if(s == "0") break;
		cnt = 0;
		for(ll i = 1; i <= now; i++)
			if(!isremove(i)) score[++cnt] = stu[i].total;
		sort(score + 1, score + cnt + 1);
		if(isdigit(s[0]))
			for(auto pos : pos2[s])
				if(!isremove(pos)){
					ll rank = lower_bound(score + 1, score + cnt + 1, stu[pos].total) - score;
					cout << rank << " " << stu[pos].sid << " ";
					cout << stu[pos].cid << " " << stu[pos].name << " ";
					printf("%lld %lld %lld %lld %lld %.2lf\n", stu[pos].c, stu[pos].m, stu[pos].e, stu[pos].p, stu[pos].total, stu[pos].average + eps);
				}
		else
			for(auto pos : pos1[s])
				if(!isremove(pos)){
					ll rank = lower_bound(score + 1, score + cnt + 1, stu[pos].total) - score;
					cout << rank << " " << stu[pos].sid << " ";
					cout << stu[pos].cid << " " << stu[pos].name << " ";
					printf("%lld %lld %lld %lld %lld %.2lf\n", stu[pos].c, stu[pos].m, stu[pos].e, stu[pos].p, stu[pos].total, stu[pos].average + eps);
				}
	}
}
void Show_ranking(){
	printf("Showing the ranklist hurts students\' self-esteem. Don\'t do that.\n");
}
void Show_Statistics(){
	printf("Please enter class ID, 0 for the whole statistics.\n");
	ll num;
	cin >> num;
	ll cnt = 0;
	double a1 = 0, a2 = 0, a3 = 0, a4 = 0;
	ll p1 = 0, p2 = 0, p3 = 0, p4 = 0;
	ll f1 = 0, f2 = 0, f3 = 0, f4 = 0;
	ll t4 = 0, t3 = 0, t2 = 0, t1 = 0, t0 = 0;
	for(ll i = 1; i <= now; i++)
		if(!isremove(i) && (!now ? 1 : stu[i].cid == num)){
			ll temp = 0;
			cnt++;
			a1 += stu[i].c;
			if(stu[i].c > 59) p1++, temp++;
			else f1++;
			a2 += stu[i].m;
			if(stu[i].m > 59) p2++, temp++;
			else f2++;
			a3 += stu[i].e;
			if(stu[i].e > 59) p3++, temp++;
			else f3++;
			a4 += stu[i].p;
			if(stu[i].p > 59) p4++, temp++;
			else f4++;
			if(!temp) t0++;
			if(temp == 1) t1++;
			if(temp == 2) t2++;
			if(temp == 3) t3++;
			if(temp == 4) t4++;
			t3 += t4; t2 += t3; t1 += t2;
		}
	a1 /= cnt; a2 /= cnt; a3 /= cnt; a4 /= cnt;
	a1 += eps; a2 += eps; a3 += eps; a4 += eps;
	printf("Chinese\n");
	printf("Average Score: %.2lf\n", a1);
	printf("Number of passed students: %lld\n", p1);
	printf("Number of failed students: %lld\n\n", f1);
	printf("Mathematics\n");
	printf("Average Score: %.2lf\n", a2);
	printf("Number of passed students: %lld\n", p2);
	printf("Number of failed students: %lld\n\n", f2);
	printf("English\n");
	printf("Average Score: %.2lf\n", a3);
	printf("Number of passed students: %lld\n", p3);
	printf("Number of failed students: %lld\n\n", f3);
	printf("Programming\n");
	printf("Average Score: %.2lf\n", a4);
	printf("Number of passed students: %lld\n", p4);
	printf("Number of failed students: %lld\n\n", f4);
	printf("Overall:\n");
	printf("Number of students who passed all subjects: %lld\n", t4);
	printf("Number of students who passed 3 or more subjects: %lld\n", t3);
	printf("Number of students who passed 2 or more subjects: %lld\n", t2);
	printf("Number of students who passed 1 or more subjects: %lld\n", t1);
	printf("Number of students who failed all subjects: %lld\n", t0);
}
int main(){
	while(1){
		welcome();
		scanf("%lld", &op);
		switch(op){
			case 0:                 return 0;
			case 1:             Add(); break;
			case 2:          Remove(); break;
			case 3:           Query(); break;
			case 4:    Show_ranking(); break;
			case 5: Show_Statistics(); break;
		}
	}
	return 0;
}