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<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<stack>
#include<queue>
#include<sstream>
#include<string>
#include<set>
#include<stdio.h>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i);

using namespace std;


struct l{
	int s,t,n,m;
	
	l(){}
	
	l(int _s,int _t,int _n,int _m){
		s=_s;t=_t;n=_n;m=_m;
	}
};



int compute_time(int ts, int te,vector<l> login) {
	int count = 0;
	int time = 0;
	int table[1261];
	fill_n((int *)table,sizeof(table)/sizeof(int),0);
	for (int i=0; i<login.size(); i++) {
		table[login[i].t] += 2*login[i].s-1;
	}
	for (int i=0; i<=1260; i++) {
		count += table[i];
		if (count > 0 && ts <= i && i < te) {
			time++;
		}
	}
	return time;
}

int main(){
	while(1){
		vector<vector<l>> login(10001,vector<l>());
		int n,m,r,q;
		cin >> n >> m;
		if(n==0 && m==0) break;
		cin >> r;
		rep(i,r){
			int t,n,m,s;
			cin >> t >> n >> m >> s;
			login[m].push_back(l(s,t,n,m));
		}
		
		cin >> q;
		rep(i,q){
			int ts,te,m;
			cin >> ts >> te >> m;
			cout << compute_time(ts, te, login[m]) << endl;
		}
	}
	return 0;
}

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

int main(){
		  int N,M,r,q,loop,sum;
		  vector<int> st[1001],end[1001];
		  int count[1001];
		  int t,n,m,s;
		  int ts,te,qm;

		  while(1){
					 cin>>N>>M;
					 if(N==0) break;
					 memset(count,0,sizeof(count));

					 cin>>r;
					 for(int i=0;i<r;i++){
								cin>>t>>n>>m>>s;
								if(s==1){
										  count[m]+=1;
										  if(count[m]==1) st[m].push_back(t);
								}
								else if(s==0){
										  count[m]-=1;
										  if(count[m]==0) end[m].push_back(t);
								}
					 }

					 cin>>q;
					 for(int i=0;i<q;i++){
								cin>>ts>>te>>qm;

								loop=0;sum=0;
								while(1){
										  if(loop==st[qm].size()) break;
										  else if(st[qm][loop]>te) break;
										  else if(st[qm][loop]<ts && end[qm][loop]<ts){
										  }
										  else if(st[qm][loop]<=ts && end[qm][loop]>ts && end[qm][loop]<=te){
													 sum+=end[qm][loop]-ts;
										  }
										  else if(st[qm][loop]<=ts && end[qm][loop]>=te){
													 sum+=te-ts;
										  }
										  else if(st[qm][loop]>ts && end[qm][loop]<=te){
													 sum+=end[qm][loop]-st[qm][loop];
										  }
										  else if(st[qm][loop]<te && end[qm][loop]>te){
													 sum+=te-st[qm][loop];
										  }
										  loop++;
								}
								cout<<sum<<endl;
					 }
					 for(int i=0;i<M;i++){
								while(!st[i].empty()){
										  st[i].pop_back();
										  end[i].pop_back();
								}
					 }
		  }
		  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

typedef struct{

  int s_cnt,e_cnt;
  int s_time[1000],e_time[1000];
  
}Record;

int main(){
  
  int N,M;
  int r,q,t,n,m,m2,s;
  int t_s,t_e;
  int table[10000];
  
  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_time[student[m].s_cnt]=t;
	student[m].s_cnt++;
      }else{
	student[m].e_time[student[m].e_cnt]=t;
	student[m].e_cnt++;
      }
    }
    
    cin >>q;
    for(int i=0 ; i < q ; i++){
      cin >>t_s>>t_e>>m2;
      for(int j=0 ; j < 10000 ; j++)table[j]=0;
      for(int j=0 ; j < student[m2].s_cnt ; j++){
	for(int k=student[m2].s_time[j]-540 ; k < student[m2].e_time[j]-540 ; k++){
	  table[k]=1;
	}
      }
      int sum=0;
      for(int j=t_s-540 ; j < t_e-540  ; j++)sum+=table[j];
      cout <<sum<<endl;
    }
    
  }
  
  return 0;
}