Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		M, T, P, R := io.NextInt(), io.NextInt(), io.NextInt(), io.NextInt()
		if M == 0 {
			break
		}
		score := make([]struct{ num, time, index int }, T)
		submit := make([][]int, T)
		for i := 0; i < T; i++ {
			score[i].index = i + 1
			submit[i] = make([]int, P)
		}

		for i := 0; i < R; i++ {
			m, t, p, j := io.NextInt(), io.NextInt()-1, io.NextInt()-1, io.NextInt()
			if j == 0 {
				score[t].num++
				score[t].time += submit[t][p]*20 + m
			} else {
				submit[t][p]++
			}
		}
		sort.SliceStable(score, func(i, j int) bool {
			return score[i].num < score[j].num || score[i].num == score[j].num && score[i].time > score[j].time
		})

		for i := T - 1; i > 0; i-- {
			io.Printf("%d", score[i].index)
			if score[i].num == score[i-1].num && score[i].time == score[i-1].time {
				io.Printf("=")
			} else {
				io.Printf(",")
			}
		}
		io.Println(score[0].index)
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>

#define REP(i,n) for( int i = 0; i < n; i++ )


using namespace std;

/*
 より多くの問題に正解したチームを上位とする．
 正解した問題数が同じ場合は，所要時間合計の少ないチームを上位とする．
 複数のチームが同数の問題に正解し，所要時間合計も同じなら，それらのチームを同順位とする．
 */

struct team{
	int ans,time,name;
    int q[50];
    fill( q, q + 50, 0 );
	team() : ans(0), time(0), name(0) {}
    
    bool operator <( const team& Right )const {
        return  ans != Right.ans ? ans < Right.ans :
        time != Right.time ? time > Right.time :
        name <  Right.name;
    }
};


int main()
{
	int M,T,P,R;
	// Mは，コンテストの始まりから終わりまでの時間である． Tは，チーム数である． Pは，問題数である． Rは，提出記録の数である
	while( cin >> M >> T >> P >> R )
	{
		int m,t,p,k;
		vector<team> team_array(T+1);
		if( T == 0 ) return 0;
		for( int i = 1; i <= T; i++)
			team_array[i].name = i;
		// mkは，経過時間である． tkは，チーム番号である． pkは，問題番号である． jkは，判定結果を表す（0なら正解，0以外なら不正解）
		REP(i,R)
		{
			cin >> m >> t >> p >> k;
			team &tm = team_array[t];
			if( !k ){
				tm.ans++;
				tm.time += m;
                if( tm.q[p] )
                    tm.time += 20 * tm.q[p];
			}
            else{
                tm.q[p]++;
            }
            
		}
		
        sort( team_array.begin() + 1 , team_array.end() );
		
        for( int i = T; i > 0; i-- )
        {
            char c;
            if( i == 1 ){
                cout << team_array[i].name << endl;
                continue;
            }
            else if ( team_array[i].ans == team_array[i-1].ans &&
                team_array[i].time == team_array[i-1].time) {
                c = '=';
            }
            else{
                c = ',';
            }
			cout << team_array[i].name << c;
        }
        
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#define f first 
#define sf second.first 
#define ss second.second 
using namespace std;
typedef pair<int,int> P;
typedef pair<int,P > iP;

int main(){
  int t,p,r,b;
  while(cin>>b>>t>>p>>r&&t){
    iP a[51];
    int k[11][51]={};
    a[0]=iP(-1,P(-1,-1));
    for(int i=1;i<=t;i++)a[i]=iP(0,P(0,i));
    for(int i=0;i<r;i++){
      int ti,pi,m,s;
      cin>>m>>ti>>pi>>s;
      if(!s)a[ti].f++,a[ti].sf-=m+k[pi][ti]*20;
      else k[pi][ti]++;
    }
    sort(a+1,a+t+1);
    for(int i=t;i>0;i--){
      cout<<a[i].ss;
      if(i!=1)
	if(a[i-1].f==a[i].f&&a[i-1].sf==a[i].sf)cout<<"=";
	else cout<<",";
    }
    cout<<endl;
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> P;
P info[51][11];
//bool team[51];
vector<P> v;

map<int, P> mp;
//int D[51];
vector<int> order;

//自作の比較関数
bool comp(P lhs, P rhs){
	if(lhs.first != rhs.first){
		return lhs.first < rhs.first;
	}
	if(lhs.second != rhs.second){
		return lhs.second > rhs.second;
	}
}

int main(){
while(1){//start


	int M, T, P, R;
	cin >> M >> T >> P >> R;
	if(M == 0 and T == 0 and P == 0 and R == 0) break;

	//初期化
	for(int i = 0; i < 51; i++){
		for(int j = 0; j < 11; j++){
			info[i][j].first = 0;
			info[i][j].second = 0;
		}
	}
	bool team[51] = {0};
	int D[51] = {0};
	int OK[51] = {0};

	//データを格納
	for(int i = 0; i < R; i++){
		int m, t, p, j;
		cin >> m >> t >> p >> j;
		team[t] = true;

		if(j == 0){
			info[t][p].second = m + 20*info[t][p].first;
			OK[t-1] += 1;
		}
		else{
			info[t][p].first += 1;
		}
	}

	//vの内部はキーがチーム名(解いた数/合計時間)
	for(int i = 1; i <= T; i++){
			int sum = 0, ok = 0;
			for(int j = 0; j < 11; j++) sum += info[i][j].second;
			//for(int j = 0; j < 11; j++) if(info[i][j].second) ok += 1;
			int tmp = OK[i-1];
			v.push_back(make_pair(tmp, sum));
			mp[i] = make_pair(tmp, sum);
	}

	sort(v.begin(), v.end(), comp);
	reverse(v.begin(), v.end());
	//debug
	//for(int i = 0; i < (int)v.size(); i++) cout << v[i].first << " " << v[i].second << endl;

	//重複カウンタを作成
	int d = 1;
	D[0] = 1;
	for(int i = 1; i < (int)v.size(); i++){
		if(v[i-1].first == v[i].first and v[i-1].second == v[i].second){
			D[i] = d;
		}
		else{
			d++;
			D[i] = d;
		}
	}

	//debug
	//for(int i = 0; i < (int)v.size(); i++) cout << D[i] << endl;

	//ソート結果にチーム名を割り当てる
	bool vis[51] = {false};
	for(int i = 0; i < (int)v.size(); i++){
		for(int j = (int)v.size(); 1 <= j; j--){
			if(v[i] == mp[j]){
				if(vis[j] == false){
					order.push_back(j);
					vis[j] = true;
				}
			}
		}
	}

	//debug
	//for(int i = 0; i < (int)v.size(); i++) cout << order[i] << endl;

	//出力
	//まず重複数を記録する
	int num[51] = {0};
	for(int i = 0; i < 51; i++) num[D[i]] += 1;

	string ans = "A";
	int idx = 0;
	for(int i = 1; i <= (int)order.size(); i++){
		if(num[i] == 0) break;
		else if(num[i] == 1){
			ans += to_string(order[idx]);
			idx++;
		}
		else{
			for(int j = 0; j < num[i]; j++){
				if(j == num[i]-1) ans += to_string(order[idx]);
				else ans += to_string(order[idx]) + "=";
				idx++;
			}
		}
		ans += ",";
	}

	ans.erase(ans.begin() + 0);
	ans.erase(ans.end() - 1);
	cout << ans << endl;

	//初期化
	v.clear();
	mp.clear();
	order.clear();
	
	ans="A";


}//end

	return 0;
}