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

using namespace std;

struct Team{
    int solve;
    int time;
    int id;
    vector<int> wa;
    vector<bool> solved;
    Team(int P){
        solve = time = 0;
        solved.resize(P);
        wa.resize(P);
    }
    bool operator < (const Team& t) const {
        if(solve != t.solve) return solve > t.solve;
        if(time != t.time)  return time < t.time;
        return id > t.id;
    }
};

int main(){
    int M, T, P, R;
    while(cin >> M >> T >> P >> R) {
        vector<Team> teams(T, Team(P));
        REP(i, T) teams[i].id = i + 1;

        REP(i, R) {
            int m, t, p, j;
            cin >> m >> t >> p >> j;
            t--;
            p--;
            if(j == 0) {
                if(teams[t].solved[p]) continue;
                teams[t].solved[p] = true;
                teams[t].time += 20 * teams[t].wa[p] + m;
                teams[t].solve += 1;
            } else {
                teams[t].wa[p] += 1;
            }
        }

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

        for(int i = 0; i < T; i++) {
            if(i > 0) {
                if(teams[i - 1].solve == teams[i].solve && teams[i - 1].time == teams[i].time) {
                    cout << "=";
                } else {
                    cout << ",";
                }
            }
            cout << teams[i].id;
        }
        cout << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;



int main()
{
    while (1) {
        int mm,m,tt,t,pp,p,rr,r;
        cin >> mm >> tt >> pp >> rr;
        
        struct Teem{
            int problem[10] = {0};
            int judge[10] = {0};
        }teem[50];
        
        int sum[51] = {0};
        int ans[51] = {0};
        
        for (int i = 0; i < rr; i++ ) {
            cin >> m >> t >> p >> r;
            
            if (r == 0) {
                sum[t] = sum[t] + m + teem[t].judge[p];
                ans[t]++;
            }else{
                teem[t].judge[p] += 20;
            }
        }
        
        int max = 0;
        vector<int> times = {0};
        int count = 0;
        
        for (int i = 1; i < tt; i++ ) {
            if (max == ans[i]) {
                times.push_back(sum[i]);
                count++;
            }
            if (max < ans[i]) {
                max = ans[i];
                times = {0};
                times.push_back(sum[i]);
                count=1;
            }
        }
        sort(times.begin(), times.end(), greater<int>());
        
        int tmp1 = -1,tmp2 = -1;
        for (int i = max; i > 0; i--) {
            for (int k = count-1; k >= 0; k--) {
                for (int m =tt; m > 0; m--) {
                    if (i == ans[m]) {
                        if (times[k] == sum[m]) {
                            if (tmp2 == ans[m]) {
                                if (tmp1 == sum[m]) {
                                    cout << "=" ;
                                }else{
                                    cout << "," ;
                                }
                            }
                            else if(tmp2 != -1 && tmp1 != -1){
                                cout << "," ;
                            }
                            cout << m ;
                            tmp1 = sum[m];
                            tmp2 = ans[m];
                            ans[m] = -1;
                        }
                    }
                }
            }

            max = 0;
            times = {0};
            count = 0;
            for (int x = 1; x < tt; x++ ) {
                if (max == ans[x]) {
                    times.push_back(sum[x]);
                    count++;
                }
                if (max < ans[x]) {
                    max = ans[x];
                    times = {0};
                    times.push_back(sum[x]);
                    count=1;
                }
            }
            sort(times.begin(), times.end(), greater<int>());
        }
        for (int i = tt; i > 0; i--) {
            
            if (ans[i] == 0) {
                if (tmp2 == -1) {
                    
                }else {
                    if (tmp2 == 0) {
                        cout << "=";
                    }else {
                        cout << ",";
                    }
                }
                cout << i ;
                tmp2 = 0;
            }
        }
        cout << endl;
        if (tmp1 == -1) {
            break;
        }
    }
    
    
    return 0;
}