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>
using namespace std;

int main(){
  int M,T,P,R;
  while(cin >> M >> T >> P >> R){
    if(M==0)break;
    vector<int> times(T,0), solved(T,0);
    vector< vector<int> > WA(T, vector<int>(10,0) );

    for(int i=0;i<R;i++){
      int m,t,p,j;
      cin >> m >> t >> p >> j;
      t--; p--;
      if(j==0){
	solved[t]++;
	times[t] += m + WA[t][p] * 20;
      }else{
	WA[t][p]++;
      }
    }

    vector< vector<int> > rank;
    for(int i=0;i<T;i++){
      vector<int> tmp;
      tmp.push_back(-solved[i]);
      tmp.push_back(times[i]);
      tmp.push_back(-i);
     
      rank.push_back(tmp);
    }

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

    for(int i=0;i<T;i++){
      cout << rank[i][2];
      if(i+1==T)cout << endl;
      else if(rank[i][0] == rank[i+1][0] && rank[i][1] == rank[i+1][1]){
	cout << "=";
      }else cout << ",";
    }
  }
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#include<algorithm>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

struct result{
    short team;
    int accepted;
    int time;
};

int main(){
    int M, T, P, R;
    while(cin >> M >> T >> P >> R, M||T||P||R){
        int data[55][15];
        rep(i,55){
            rep(j,15){
                data[i][j] = -100;
            }
        }
        int m,t,p,r;
        rep(i,R){
            cin >> m >> t >> p >> r;
            t--; p--;
            if(r == 0){
                if(data[t][p] < 0){
                    data[t][p] = m + (-1 * data[t][p] - 100) * 20;
                }else{
                    data[t][p] = m;
                }
            }else{
                data[t][p]--;
            }
        }
        struct result res[55];
        rep(i,T){
            int accepted = 0;
            int time = 0;
            rep(j,P){
                if(data[i][j] != -100 && data[i][j] != -1){
                    accepted++;
                    time+= data[i][j];
                }
            }
            res[T - 1 - i].team = i + 1;
            res[T - 1 - i].accepted = accepted;
            res[T - 1 - i].time = time;
        }
        rep(i,T - 1){
            for(int j = T - 1; j > i; j--){
                if(res[j].accepted > res[j - 1].accepted){
                    struct result g = res[j];
                    res[j] = res[j - 1];
                    res[j - 1] = g;
                }
            }
        }
        rep(i,T){
            rep(j,T){
                if(res[j].accepted == res[j + 1].accepted && res[j].time > res[j + 1].time){
                    struct result g = res[j];
                    res[j] = res[j + 1];
                    res[j + 1] = g;
                }
            }
        }
        rep(i,T){
            if(i && res[i - 1].accepted == res[i].accepted && res[i - 1].time == res[i].time){
                cout << '=';
            }else if(i){
                cout << ',';
            }
            cout << res[i].team;
        }
        cout << endl;
    }
}