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;

int main(){
    int m,t,p,r;
    while(cin>>m>>t>>p>>r,m){
        vector<vector<int>> team(t,vector<int>(p,0));
        for(int i=0;i<r;i++){
            int mm,tt,pp,jj;
            cin>>m>>tt>>pp>>jj;
            if(!jj)
                team[tt-1][pp-1]=m+(-team[tt-1][pp-1])*20;
            else
                team[tt-1][pp-1]--;

        }
        vector<tuple<int,int,int>> rank(t,make_tuple(0,0,0));
        for(int i=0;i<t;i++)
            get<2>(rank[i])=i+1;
        for(int i=0;i<t;i++){
            for(int j=0;j<p;j++)
                if(team[i][j]>0){
                    (get<0>(rank[i]))++;
                    get<1>(rank[i])-=team[i][j];
                }


        }
        sort(rank.begin(),rank.end(),greater<tuple<int,int,int>>());
        queue<int> q;
        pair<int,int> pre=make_pair(-1,-1);
        string res="";
        for(int i=0;i<t;i++){
            if(pre==make_pair(get<0>(rank[i]),get<1>(rank[i]))){
                q.push(get<2>(rank[i]));
                continue;
            }
            else{
                if(!res.empty())
                    res+=",";
                int s=q.size();
                for(int j=0;j<s;j++){
                    int a=q.front();
                    if(j!=s-1){
                        res+=to_string(a)+"=";
                        }
                    else
                        res+=to_string(a);

                    q.pop();

                }
                q.push(get<2>(rank[i]));
                pre=make_pair(get<0>(rank[i]),get<1>(rank[i]));
            }

        }
        if(!q.empty())
            res+=',';
        for(int i=0;!q.empty();i++){
            if(q.size()!=1){
                res+=to_string(q.front())+"=";

            }
            else
                res+=to_string(q.front());
            q.pop();
        }
        cout<<res<<endl;
    }

    return 0;
}

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

using namespace std;

int M, T, P, R;

struct DATA{
  int id, t, sv;
  vector<int> pr, pt;
  DATA(int id_): id(id_), t(0), sv(0), pr(P,false), pt(P,0){} 
  bool operator ==(const DATA& a){
    return (sv==a.sv && t==a.t);
  }
};

bool comp(const DATA& a, const DATA& b){
  if(a.sv != b.sv) return a.sv > b.sv;
  if(a.t != b.t) return a.t < b.t;
  return a.id > b.id;
}

int main(){
  int m, t, p, is;
  vector<DATA> data;
  while(1){
    cin >> M >> T >> P >> R;
    if(!M && !T && !P && !R) break;
    data.clear();
    for(int i=1; i<=T; ++i) data.push_back(DATA(i));
    for(int i=0; i<R; ++i){
      cin >> m >> t >> p >> is;
      --t; --p;
      if(is){
	++data[t].pt[p];
      }else if(!data[t].pr[p]){
	data[t].t += m + 20 * data[t].pt[p];
	++data[t].sv;
	data[t].pr[p] = true;
      }
    }
    sort(data.begin(), data.end(), comp);
    cout << data[0].id;
    for(int i=1; i<data.size(); ++i){
      cout << (data[i]==data[i-1] ? '=' : ',') << data[i].id;
    }
    cout << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<tuple>
#include<set>
#include<map>
#include<algorithm>
using namespace std;

struct Record {
  int tid, pid, time;
  bool correct;
};

struct Team {
  Team() {
    penalty = 0;
  }
  set<int> solved;
  map<int, int> WA;
  int penalty;
};

// Solved Problems, Penalty, Team ID
typedef tuple<int, int, int> Score;

int main() {
  int M, T, P, R;
  while (cin >> M >> T >> P >> R && M) {
    vector<Record> records(R);
    for (int i = 0; i < R; i++) {
      int m, t, p, j;
      cin >> m >> t >> p >> j;
      records[i].pid = --p;
      records[i].tid = --t;
      records[i].time = m;
      records[i].correct = (j == 0);
    }

    vector<Team> teams(T);
    for (Record r : records) {
      if (teams[r.tid].solved.find(r.pid) != teams[r.tid].solved.end()) {
        continue;
      } else if (r.correct) {
        teams[r.tid].solved.insert(r.pid);
        teams[r.tid].penalty +=
          teams[r.tid].WA[r.pid] * 20 + r.time;
      } else {
        teams[r.tid].WA[r.pid]++;
      }
    }

    vector<Score> team_result(T);
    for (int i = 0; i < T; i++) {
      get<0>(team_result[i]) = -teams[i].solved.size();
      get<1>(team_result[i]) = teams[i].penalty;
      get<2>(team_result[i]) = -i;
    }

    sort(team_result.begin(), team_result.end());

    for (int i = 0, len = team_result.size(); i < len; i++) {
      Score s = team_result[i];
      if (i > 0) {
        Score p = team_result[i - 1];
        cout << 
          (get<0>(p) == get<0>(s) && get<1>(p) == get<1>(s)?"=":",");
      }
      cout << -get<2>(s)+1;
    }
    cout << endl;
  }
}