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>
using namespace std;

int table[10001][1261];

int main(){
  int N, M, r, q, t, s, n, m,ts,te;

  while(cin >> N >> M, N && M){
    cin >> r;
    for(int i= 0; i < 10001; i++){
      for(int j = 0; j < 1261; j++){
	table[i][j] = 0;
      }
    }
    
    for(int i = 0; i < r; i++){
      cin >> t >> n >> m >> s;
      if(s) table[m][t]++;
      else  table[m][t]--;
    }
    for(int i = 1; i <= M; i++){
      for(int j = 540; j <= 1260; j++){
	table[i][j] += table[i][j-1];
      }
    }
 
    for(int i = 1; i <= M; i++){
      for(int j = 540; j <= 1260; j++){
	//if(i == 1)cout << table[i][j] << endl;
	if(table[i][j] > 1) table[i][j] = 1;
	table[i][j] += table[i][j-1];
      }
    }
    cin >> q;
    for(int i = 0; i < q; i++){
      cin >> ts >> te >> m;
      cout << table[m][te-1] - table[m][ts-1] << endl;
    }
    /*for(int i = 540; i < 1260; i++) {cout << i << " " << table[1][i];
    if(i == te || i == ts) cout << "ttt";
    cout << endl;}
    */
  }
}

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

using namespace std;

const int MaxN = 1001;
const int MaxM = 10001;

int N, M;

int main() {
  int count[MaxM];

  while(cin>>N>>M && !(N==0 && M==0)) {
    vector < vector< pair<int,int> > > logg(MaxM);
    int r;
    cin>>r;
    int t,n,m,s;
    for(int i=0; i<MaxM; i++) { // 初期化
      count[i] = 0;
    }
    for(int i=0; i<r; i++) {
      cin>>t>>n>>m>>s;
      if(s == 1) { // login
	count[m]++;
	if(count[m] == 1) {
	  logg[m].push_back(make_pair(t,t));
	}
      }
      else { // logout
	count[m]--;
	if(count[m] == 0) {
	  logg[m].back().second = t;
	}
      }
    }
    int q;
    cin>>q;
    for(int i=0; i<q; i++) {
      int ts, te, m, ans = 0;
      cin>>ts>>te>>m;
      int ans1, ans2; // 4debug ans1は誤りらしい
      for(int j=0; j<logg[m].size(); j++) {
	if(logg[m][j].first <= te) {
	  ans1 = min(te, logg[m][j].second)-max(ts, logg[m][j].first);
	}
	ans2 = max(0, min(te,logg[m][j].second)-max(ts,logg[m][j].first));
        if(ans1!=ans2) {
	  cout<<"Q: "<<ts<<" "<<te<<endl;
	  cout<<"why: "<<min(te, logg[m][j].second)-max(ts, logg[m][j].first)<<endl;
	  cout<<"val: "<<logg[m][j].first<<" "<<logg[m][j].second<<endl;
	  cout<<"ans: "<<ans1<<" "<<ans2<<endl;
        }
        ans += ans2;
      }
      cout<<ans<<endl;
    }
  }
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> P;

struct Log{
  int t;
  int n;
  int m;
  int s;
};

struct Query{
  int ts;
  int te;
  int m;
};


void displayLog(vector<Log> L, int r){
  for(int i = 0; i < r; i++){
	cout << L[i].t << " " << L[i].n << " " << L[i].m << " " << L[i].s << endl;
  }
  cout << endl;
}

void displayQuery(vector<Query> Q, int q){
  for(int i = 0; i < q; i++){
	cout << Q[i].ts << " " << Q[i].te << " " << Q[i].m << endl;
  }
  cout << endl;
}

template <typename T> void displayTmp(T tmp_time, int M){
  
  for(int i = 0; i < M; i++){
	cout << "tmp_time[" << i << "] = ";
	cout << tmp_time[i].first << " " << tmp_time[i].second << endl; 
  }
  cout << endl;
}

void displayLogin_t(vector<vector<P> > login_t, int M){
  for(int i = 0; i < M; i++){
	cout << "login_t[" << i << "] = ";
	for(int j = 0; j < login_t[i].size(); j++){
	  cout << " ( " << login_t[i][j].first << ", " << login_t[i][j].second << " )";
	}
	cout << endl;
  }
  cout << endl;
}


int main(){
  int N, M, r, q;
  while(1){
    cin >> N >> M;
    if(N == 0 && M == 0) break;

	cin >> r;
    vector<Log> L;

	for(int i = 0; i < r; i++){
	  Log tmp;
	  cin >> tmp.t >> tmp.n >> tmp.m >> tmp.s;
	  L.push_back(tmp);
    }
	
    cin >> q;
    vector<Query> Q;

	for(int i = 0; i < q; i++){
	  Query tmp;
	  cin >> tmp.ts >> tmp.te >> tmp.m;
	  Q.push_back(tmp);
    }

	vector<int> student(M, 0);
	vector<vector<P> > login_t(M);
	vector<P> tmp_time(M, P(0, 0));
	
	for(int i = 0; i < r; i++){
	  if(L[i].s == 1){
		if(student[L[i].m - 1] == 0){
		  student[L[i].m - 1]++;
		  tmp_time[L[i].m - 1].first = L[i].t;
 		}
		else{
		  student[L[i].m - 1]++;
		}
	  }
	  else{
		if(student[L[i].m - 1] == 1){
		  student[L[i].m - 1]--;
		  tmp_time[L[i].m - 1].second = L[i].t;
		  login_t[L[i].m - 1].push_back(tmp_time[L[i].m - 1]);
		}
		else{
		  student[L[i].m - 1]--;
		}
	  }
	}

	for(int i = 0; i < q; i++){
	  int qs = Q[i].ts;
	  int qe = Q[i].te;
	  int id = Q[i].m - 1;
	  int ans = 0;
	  
	  for(int j = 0; j < login_t[id].size(); j++){
		int ls = login_t[id][j].first;
		int le = login_t[id][j].second;
		if(qs < ls && ls <= qe && qe <= le){
		  ans += qe - ls;
		}
		else if(ls < qs && qe < le){
		  ans += qe - qs;
		}
		else if(ls <= qs && qs < le && le < qe){
		  ans += le - qs;
		}
		else if(qs <= ls && le <= qe){
		  ans += le - ls;
		}
	  }
	  cout << ans << endl;
	}
  }
  return 0;
}