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 <bits/stdc++.h>

#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)

using namespace std;

int n,m;
int pc[1000][1310];

int main(void){
	while(cin >> n >> m){
		if(n==0&&m==0) break;
		rep(i,1000)rep(j,1310) pc[i][j]=0;

		int r; cin >> r;
		rep(i,r){
			int t,a,b,s;
			cin >> t >> a >> b >> s;
			if(s==1)
				pc[a-1][t]+=b;
			else
				pc[a-1][t]-=b;
		}
		rep(i,n)rep(j,1300) pc[i][j+1]+=pc[i][j];
		int q; cin >> q;
		rep(loop,q){
			int ts,te,tm;
			cin >> ts >> te >> tm;
			int ans=0;
			for(int t=ts;t<te;++t){
				bool check=false;
				rep(i,n) if(pc[i][t]==tm) check=true;
				if(check) ans++;
			}
			cout << ans << endl;
		}
	}
	return 0;
}

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]; 
	//	students[i][j] += students[i][j-1];
      }
    }

    // ??????
    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;
      //      cout << students[id][te] - students[id][ts] << endl;
      //cout << students[id][te] - students[id][ts] << endl;
    }
  }
}

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

struct Data{

  int s_cnt,e_cnt;
  int s_time[500],e_time[500];
  
};

int main(){
  
  int N,M;
  int r,q,t,n,m,m2,s;
  int t_s,t_e;
  int table[1000];
  
  while(1){
    
    cin >>N>>M;
    if(N==0 && M==0)break;
    
    vector<Data> 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 < 1000 ; 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;
}

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

int main(){
  int N,M;
  while(cin>>N>>M){
    if(N==0)break;
    int r,q;
    int student[M][721];
    memset(student,0,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(t>0 && 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;
      cin>>ts>>te>>m;
      ts-=540;te-=540;m--;
      int ans=0;
      for(int i=ts;i<te;i++){
	if(student[m][i]>0)ans++;
      }
      cout << ans << endl;
    }
  }
  return 0;
}

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

std::map<int, int> PC[1001];
int N,M,r,t,n,m,s;

int solve(int s, int e, int m){
	int ans = 0;
	bool usd[1001] = {false};

	for(int i=540; i<=1260; i++){
		for(int j=1; j<=N; j++){
			if(usd[j] && i>s && i<=e){
				ans++;
				break;
			}
		}

		for(int j=1; j<=N; j++){
			if(PC[j][i] == m)
				usd[j] = !usd[j];
		}
	}

	return ans;
}

int main(){
using namespace std;
	while(1){
		cin >> N >> M;
		if(!N && !M)
			break;
			
		cin >> r;
		for(int i=0; i<r; i++){
			cin >> t >> n >> m >> s;
			PC[n][t] = m;
		}
		
		cin >> r;
		for(int i=0; i<r; i++){
			cin >> s >> t >> m;
			cout << solve(s,t,m) << endl;
		}
		
		for(int i=1; i<=N; i++)
			PC[i].clear();
	}
	
	return 0;
}