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 <cstdio>
#include <cstdlib>
#include <algorithm>

using namespace std;

int main()
{
	int N, M;
	int r, q;
	int t, n, m, s, ts, te;
	int sum;
	int ans[1260-540];

	while(true){
		cin >> N >> M;
		if(N==0 && M==0){return 0;}

		int* pc = new int[(N+1)*(1260-540)]; //pc毎のアクセス履歴
		int* in_time = new int[N+1]; //pc毎の直前のログイン情報(時間)
		int* in_m = new int[N+1]; //pc毎の直前のログイン情報(学生)
		fill_n(pc,(N+1)*(1260-540),0); fill_n(in_time,N+1,0); fill_n(in_m,N+1,0);

		cin >> r;
		for(int i=0; i<r; i++){
			cin >> t >> n >> m >> s;
			if(s==1){
				in_time[n] = t;
				in_m[n] = m;
			}
			else{
				for(int j= in_time[n]-540; j< t-540; j++){
					pc[n*(1260-540)+j] = m;
				}
				in_time[n] = 0;
				in_m[n] = 0;
			}
		}
		for(int i=1; i<=N; i++){
			if(in_time[i] != 0){
				for(int j= in_time[i]-540; j< 1260-540; j++){
					pc[i*(1260-540)+j] = in_m[i];
				}
				in_time[n] = 0;
				in_m[n] = 0;
			}
		}

		cin >> q;
		for(int i=0; i<q; i++){
			sum=0; fill_n(ans,1260-540,0);
			cin >> ts >> te >> m;
			for(int j=1; j<=N; j++){
				for(int k=0; k< 1260-540; k++){
					if(pc[j*(1260-540)+k]==m){
						ans[k]=1;
					}
				}
			}
			for(int k= ts-540; k< te-540; k++){
				if(ans[k]==1){
					sum++;
				}
			}
			cout << sum << endl;
		}

		delete[] pc;
		delete[] in_time;
		delete[] in_m;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) repi(i,0,n)
#define repi(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
typedef long long i64;
int main(){
  int N, M;
  while(cin>>N>>M){
    if(N==0&&M==0)break;
    int r;
    cin>>r;
    int a[M+1][1500]={0};
    for(int i=0;i<r;i++){
      
      int t,n,m,s;
      
      cin>>t>>n>>m>>s;
      //n ha tshukawanai
      if(s==1){//login

	a[m][t]++;
      }else if(s==0){//logout
	
	a[m][t+1]--;    }
      
    }
    
      repi(i,1,M+1)
	{
	  rep(j,1300)
	    {
	      if(j==0)continue;
	      a[i][j] += a[i][j-1];
	    }
	}

      int q;
      cin >> q;
      rep(i, q)
	{
	  int ts, te, mm;
	  cin >> ts >> te >> mm;
	  int cnt = 0;
	  //printf("%d %d\n", ts, te);
	  repi(j, ts+1, te)
	    {
	      //printf("%d\n" ,a[mm][j]);
	      if(a[mm][j]>0)cnt++;
	    }
	  printf("%d\n",cnt);
	}
      
     
  }
  
  return 0;
}

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

int main()
{
	int N, M;
	while (cin >> N >> M, N || M){

		//rの入力
		int r, t[1001], n[1001], m[10001], s[1001], q, ts, te, qm;
		fill(t, t + 1001, 0);
		fill(n, n + 1001, 0);
		fill(m, m + 10001, 0);
		fill(s, s + 1001, 0);

		cin >> r;
		for (int i = 0; i < r; i++){
			cin >> t[i] >> n[i] >> m[i] >> s[i];
		}
		cin >> q;

		//qの入力と計算
		for (int c = 0; c < q; c++){
			cin >> ts >> te >> qm;

			//記録
			int tm[1261];
			int pc[1261];
			fill(tm, tm + 1261, 0);
			fill(pc, pc + 1261, 0);
			for (int i = 0; i < r; i++){
				if (m[i] == qm){
					if (s[i] == 1){
						pc[n[i]] = t[i];
					}
					if (s[i] == 0){
						for (int j = pc[n[i]]; j <= t[i]; j++){
							tm[j] = 1;
						}
					}
				}
			}

			//カウント
			bool login = false;
			int counter = 0;
			int temp;
			for (int i = ts; i < te; i++){
				if (tm[i] == 1 && login == false){
					temp = i;
					login = true;
				}
				if (tm[i] == 0 && login == true){
					counter += i - 1 - temp;
					login = false;
				}
			//	cout << "i:" << i << " tm[i]:" << tm[i] << " login:" << login << " temp:" << temp << endl;
			}
			if (login == true){
				counter += te - temp;
			}
			cout << counter << endl;
		}
	}
	return 0;
}