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 <cstring>
using namespace std;

int students[10001][800] = {};
int numlogin[10001] = {};
int sum[10001][800]={};

int main(){

  while(1){
    int N,M,r;
    cin >> N >> M;
    if(!N and !M) break;
    cin >> r;

    memset(students,0,sizeof(students));
    memset(numlogin,0,sizeof(numlogin));
    memset(sum,0,sizeof(sum));

    // ?¨????
    for(int i=0; i<r; i++){ // 1000
      int t,n,m,s;
      cin >> t >> n >> m >> s;
      t -= 540;
      if(s == 0) { // ?????°??¢??????
	numlogin[m]--;
	if(numlogin[m] == 0){
	  for(int i=t-1; students[m][i] != 1 and t>=0; i--){ // 1000
	    students[m][i] = 1;
	  }
	}
      }
      else{ // ?????°??????
	numlogin[m]++;
	if(numlogin[m] == 1)
	  students[m][t] = 1;
      }
    }

    // ?´???????
    for(int i=1; i<=M; i++){ // 100000
      for(int j=1; j<=720; j++){ // 1000
	sum[i][j] = sum[i][j-1] + students[i][j]; 
      }
    }

    // ??????
    int  q;
    cin >> q;
    for(int i=0; i<q; i++){
      int ts,te,id;
      cin >> ts >> te >> id;
      ts -= 540;
      te -= 540;
      cout << sum[id][te-1] - sum[id][ts] + students[id][ts] << endl;
    }
  }
}

C++: #define _CRT_SECURE_NO_WARNINGS // #pragma warning(disable:4996)
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <functional>
#include <sstream>
#include <cmath>
#include <set>
#include <map>
#include <stack>
using namespace std; 

#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(a);i>=(b);i--)
#define pb push_back
#define mp(a,b) make_pair(a,b)
#define all(a) a.begin(),a.end()
#define len(x) ((int)(x).size())
#define tmax(a,b,c) max((a),max((b),(c)))
#define tmin(a,b,c) min((a),min((b),(c)))
#define debug(x) cerr << #x << " is " << x << endl;

typedef pair<int, int> Pii;
typedef map<int, int> Mii;
typedef vector<int> Vi;
typedef vector<vector<int> > VVi;
typedef long long ll;
const int inf = 2e9;
const ll ll_inf = 1e17;
const int mod = 1e9 + 7;
const long double eps = 1e-10;
typedef pair<ll, ll> Pll; 

int g[10001][1300];

int main()
{
	int N, M;
	while (cin>>N>>M && (N || M)) {
		fill(g[0], g[1300], 0);
		int r; cin >> r;
		rep(i,0,r) {
			int t,n,m,s;
			cin>>t>>n>>m>>s;
			if (s == 1)
				g[m][t] += 1;
			else
				g[m][t] -= 1;
		}
		rep(i,1,M+1) rep(j,540, 1260) g[i][j+1] += g[i][j];  

		int q; cin >> q;
		rep(i,0,q) {
			int s,e,m;
			cin>>s>>e>>m;
			int cnt = 0;
			rep(j,s,e) if (g[m][j]) cnt++;
			cout << cnt << endl;
		}
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define REP(i,n) for (int i=0;i<(n);i++)
#define ALL(a) (a).begin(),(a).end()
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define ll long long
#define ull unsigned long long
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

using namespace std;

int main(){
  int N,M;
  while(true){
    cin >> N >> M;
    if(!N)break;
    int r;
    cin >> r;
    vector<vector<int>> timeline(1001,vector<int>(1300,0));
    REP(i,r){
      int t,n,m,s;
      cin >> t >> n >> m >> s;
      if(s==0){
	timeline[m][t] -= 1;
      }else{
	timeline[m][t] += 1;
      }
    }
    REP(i,1001)
      for(int j = 540;j<1260;j++){
      timeline[i][j+1] += timeline[i][j];
    }
    int q;
    cin >> q;

    REP(i,q){
      int ct = 0;
      int t1,t2,m;
      cin >> t1 >> t2 >> m;
      for(int j = t1;j<t2;j++){
	if(timeline[m][j]>0)ct++;
      }
      cout << ct << endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<cstring>
using namespace std;
int student[10000][721];
int main(){
  int N,M;
  while(cin>>N>>M){
    if(N==0)break;
    int r,q;
    memset(student,-1,sizeof(student));  
    cin>>r;
    for(int i=0;i<r;i++){
      int t,n,m,s;
      cin>>t>>n>>m>>s;
      t-=540;m--;
      if(s==1){
	student[m][t]=n;
      }else{
	while(student[m][--t]!=n)
	  if(student[m][t]<=0) student[m][t]=n;
      }
    }
    cin>>q;
    for(int i=0;i<q;i++){
      int ts,te,m,ans=0;
      cin>>ts>>te>>m;
      ts-=540;te-=540;m--;
      for(int i=ts;i<te;i++){
	if(student[m][i]>0)ans++;
      }
      cout << ans << endl;
    }
  }
  return 0;
}