Go: package main

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

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		_, M := io.NextInt(), io.NextInt()
		if M == 0 {
			break
		}
		r := io.NextInt()
		t, m, s := make([]int, r), make([]int, r), make([]int, r)
		for i := 0; i < r; i++ {
			t[i], _, m[i], s[i] = io.NextInt(), io.NextInt(), io.NextInt()-1, io.NextInt()
		}
		q := io.NextInt()
		for i := 0; i < q; i++ {
			ss, ee, mm := io.NextInt(), io.NextInt(), io.NextInt()-1
			x := make([]int, 1300)
			for j := 0; j < r; j++ {
				if m[j] == mm {
					if s[j] == 1 {
						x[t[j]]++
					} else {
						x[t[j]]--
					}
				}
			}
			for j := 1; j < 1300; j++ {
				x[j] = x[j] + x[j-1]
			}
			ans := 0
			for j := ss; j < ee; j++ {
				if x[j] > 0 {
					ans++
				}
			}
			io.Println(ans)
		}
	}
}

// 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>

using namespace std;

class Record {
    public:
        int t, n, m, s;
};

int compute_time(int s, int e, vector<Record> records) {
    int count = 0;
    int time = 0;
    int table[1260];
    for (int i=0; i<1260; i++) {
        table[i] = 0;
    }
    for (int i=0; i<(int)records.size(); i++) {
        table[records[i].t] += 2*records[i].s-1;
    }
    for (int i=0; i<1260; i++) {
        count += table[i];
        if (count > 0 && s <= i && i < e) {
            time++;
        }
    }
    return time;
}

int main() {
    int n, m, r, q;
    while (true) {
        vector<Record> records[10000];
        cin >> n >> m;
        if (n == 0) {
            return 0;
        }
        for (int i=0; i<10000; i++) {
            records[i].clear();
        }
        cin >> r;
        for (int i=0; i<r; i++) {
            Record rec;
            cin >> rec.t >> rec.n >> rec.m >> rec.s;
            records[rec.m].push_back(rec);
        }
        cin >> q;
        for (int i=0; i<q; i++) {
            int s, e, m;
            cin >> s >> e >> m;
            cout << compute_time(s, e, records[m]) << endl;
        }
    }
}

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

struct Record{

  int s_cnt,e_cnt;
  int s[500],e[500];
  
};

int main(){
  
  int N,M;
  int r,q,t,n,m,S;
  int t_s,t_g;
  int table[750];
  
  while(1){
    
    cin >>N>>M;
    if(N==0 && M==0)break;
    
    Record student[M+1];
    
    for(int i=0 ; i < M+1 ; i++){
      student[i].s_cnt=0;
      student[i].e_cnt=0;
    }
    
    cin >>r;
    for(int i=0 ; i < r ; i++){
      cin >>t>>n>>m>>S;
      if(S == 1){
	student[m].s[student[m].s_cnt]=t;
	student[m].s_cnt++;
      }else{
	student[m].e[student[m].e_cnt]=t;
	student[m].e_cnt++;
      }
    }
    
    cin >>q;
    for(int i=0 ; i < q ; i++){
      cin >>t_s>>t_g>>m;
      for(int j=0 ; j < 750 ; j++)table[j]=0;
      for(int j=0 ; j < student[m].s_cnt ; j++){
	for(int k=student[m].s[j]-540 ; k < student[m].e[j]-540 ; k++){
	  table[k]=1;
	}
      }
      int sum=0;
      for(int j=t_s-540 ; j < t_g-540  ; j++)sum+=table[j];
      cout <<sum<<endl;
    }
    
  }
  
  return 0;
}

C++: #ifndef _WIN32
#include<iostream>
#endif
#include<cmath>
#include<iomanip>
#include<algorithm>
#include<functional>
#include<vector>
#include<queue>
#include<string>
#include<stdlib.h>

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

using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;

int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	cout << fixed << setprecision(30);

	while (true){
		int N, M;
		cin >> N >> M;
		if (N == 0) break;
		int r; cin >> r;

		vvi students(M, vi(1262, 0));

		REP(i, r){
			int t, n, m, s;
			cin >> t >> n >> m >> s; m--;
			if (s == 1){
				students[m][t]++;
			}
			else {
				students[m][t]--;
			}
		}

		REP(i, M) {
			FOR(j, 1, 1262){
				students[i][j] += students[i][j - 1];
			}
		}

		int q;
		cin >> q;

		REP(i, q){
			int ts, te, m;
			cin >> ts >> te >> m; m--;
			int cnt = 0;
			FOR(j, ts, te){
				if (students[m][j] >= 1) cnt++;
			}
			cout << cnt << endl;
		}
	}
	return 0;
}

C++: #include <stdio.h>
#include <string.h>

int main(void){
	int N, M, r, t, n, m, s, log[17][721], q, ts, tg, i, j, k, flag[17], count;;
	while(1){
		scanf("%d%d",&N,&M);
		if(N == 0 && M == 0)
			break;
		memset(log,0,sizeof(log));
		scanf("%d",&r);
		for(i = 0;i < r;i++){
			scanf("%d%d%d%d",&t,&n,&m,&s);
			if(s == 1)
				log[n - 1][t - 540] = m;
			else if(s == 0)
				log[n - 1][t - 540] = -1;
		}
		memset(flag,0,sizeof(flag));
		for(i = 0;i < N;i++){
			for(j = 0;j <= 720;j++){
				if(log[i][j] && flag[i] == 0)
					flag[i] = log[i][j];
				else if(log[i][j] && flag[i] != 0)
					flag[i] = 0;
				if(flag[i] != 0)
					log[i][j] = flag[i];
			}
		}
		scanf("%d",&q);
		for(i = 0;i < q;i++){
			scanf("%d%d%d",&ts,&tg,&m);
			memset(flag,0,sizeof(flag));
			count = 0;
			for(j = ts - 540;j <= tg - 540;j++){
				for(k = 0;k < N;k++){
					if(flag[k]){
						count++;
						break;
					}
				}
				for(k = 0;k < N;k++){
					if(log[k][j] == m)
						flag[k] = 1;
					else if(log[k][j] != 0)
						flag[k] = 0;
				}
			}
			printf("%d\n",count);
		}
	}
	return 0;
}