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

bool comp(pair<pair<int,int>,int> p1, pair<pair<int,int>,int> p2){

    if(p1.first.first == p2.first.first){
        if(p1.first.second == p2.first.second){
            return p1.second < p2.second;
        }
        return p1.first.second > p2.first.second;
    }
    return p1.first.first < p2.first.second;

}

int main() {

    while(1) {

        int M,T,P,R;

        cin >> M >> T >> P >> R;

        if(M == 0 && T == 0 && P == 0 && R == 0) break;

        pair<int,int> team[T+1]; //solve_num, time
        pair<bool,int> try_progrums[T+1]; //is_tryed, lasttime

        team[0] = make_pair(-1,-1);

        for(int i=1; i<T+1; i++){
            team[i] = make_pair(0,0);
            try_progrums[i] = make_pair(false,0);
        }

        for(int i=0; i<R; i++){

            int m, t, p, j;

            cin >> m >> t >> p >>j;

            if(try_progrums[t].first){
                team[t].second += 20;
            }

            if(j == 0){
                team[t].first++;
                team[t].second += m;
            }
            else{
                if(try_progrums[t].first){
                    team[t].second += m - try_progrums[t].second;
                    try_progrums[t].second = m;
                }
                else{
                    try_progrums[t].first = true;
                    try_progrums[t].second = m;
                }
            }
        }

        pair<pair<int,int>,int> team_result[T+1];

        for(int i=0; i<T+1; i++){
            team_result[i] = make_pair(make_pair(team[i].first,team[i].second),i);
        }

        sort(team_result,team_result+T+1,comp);

        cout << team_result[T].second;

        for(int i=T; i>1; i--){
            if(team_result[i].first.first == team_result[i-1].first.first && team_result[i].first.second == team_result[i-1].first.second){
                cout << '=' << team_result[i-1].second;
            }
            else{
                cout << ',' << team_result[i-1].second;
            }
        }

        cout << endl;




    }
    return 0;
}

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

int main() {
	int m, t, p, r;
	while (cin >> m >> t >> p >> r) {
		if (m == 0) break;
		vector<pair<int, int>> cnt(55);
		for (int i = 0; i < t; i++) {
			cnt[i] = make_pair(0, i);
		}
		int time[55] = {};
		int pena[55][20] = {};
		for (int i = 0; i < r; i++) {
			int a, b, c, d;
			cin >> a >> b >> c >> d;
			b--;
			if (d == 0) {
				time[b] += a + 20 * pena[b][c];
				cnt[b].first++;
			}
			else {
				pena[b][c]++;
			}
		}
		sort(cnt.begin(), cnt.end());
		reverse(cnt.begin(), cnt.end());
		vector<vector<pair<int,int>>> ac(15);
		for (int i = 0; i < t; i++) {
			ac[cnt[i].first].push_back(make_pair(time[cnt[i].second],-cnt[i].second));
		}
		bool win = true;
		for (int i = p; i >= 0; i--) {
			if (ac[i].empty()) continue;
			sort(ac[i].begin(), ac[i].end());
			if (!win) cout << ",";
			if (win) win = false;
			cout << -ac[i][0].second +1;
			
			for (int j = 1; j < ac[i].size(); j++) {
				if (ac[i][j - 1].first == ac[i][j].first) {
					cout << "=";
				}
				else cout << ",";
				cout << -ac[i][j].second + 1;
			}
		}
		cout << endl;
	}
}

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]={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;