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 <algorithm>
#include <iostream>
#include <map>
#include <utility>
#include <vector>
using namespace std;
typedef pair<int, int> pii;
int main(){
  int N, M, inf = 1000000;
  while (cin >> N >> M, N){
    int r, t, n, m, s;
    cin >> r;
    vector< vector<pii> > V(M);
    map<pii,int> L;
    for (int i = 0; i < r; ++i){
      cin >> t >> n >> m >> s;
      --m;
      if(s) L[pii(n,m)] = t;
      else V[m].push_back(pii(L[pii(n,m)],t));
    }
    int q, ts, te;
    cin >> q;
    for(int i = 0; i < q; ++i){
      cin >> ts >> te >> m;
      --m;
      sort(V[m].begin(),V[m].end());
      int ans = te-ts;
      for(int j = 0; j < V[m].size(); ++j){
	if(ts >= V[m][j].first) ts = max(ts,V[m][j].second);
	else{
	  ans += ts-V[m][j].first;
	  ts = V[m][j].second;
	}
	if(ts >= te) break;
      }
      if(ts < te) ans += ts-te;
      cout << ans << endl;
    }
  }
  return 0;
}

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

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) begin(r),end(r)
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)
#define vvl(v,w,h,init) vector<vector<ll>> v(w,vector<ll>(h,init))
#define mp(a,b) make_pair(a,b)

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using pii = pair<int,int> ;
using pll = pair<ll,ll> ;
using plll = pair<ll,pll> ;

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n,m,N,M,t,s;
  while(cin >> N >> M && N+M){
    vector<vector<plll>> v(N),v2(M);
    ll r,q;
    cin >> r;
    rep(i,r){
      cin >> t >> n >> m >> s;
      if(s){
        plll p = mp(n,mp(t,-1));
        v[n-1].push_back(p);
        v2[m-1].push_back(p);
      }
      else{
        v[n-1].back().se.se = t;
        for(int x = v2[m-1].size()-1; x >= 0; --x){
          if(v2[m-1][x].fi == n && v2[m-1][x].se.se == -1LL){
            v2[m-1][x].se.se = t;
            break;
          }
        }
      }
    }
    ll ts,te;
    cin >> q;
    ll inf = 1000000LL;
    rep(i,q){
      ll res = 0,ma = -1,mi = inf;
      cin >> ts >> te >> m;
      rep(j,v2[m-1].size()){
        auto u = v2[m-1][j].se;
        if(mi == inf){
          mi = max(ts,u.fi);
          ma = min(te,u.se);
        }
        else if(u.fi <= ma){
          mi = max(ts,min(mi,u.fi));
          ma = min(te,max(ma,u.se));
        }
        else{
          if(ma - mi > 0)
            res += ma - mi;
          mi = max(ts,u.fi);
          ma = min(te,u.se);
        }
//         if(v2[m-1][j].se.fi >= ts || v2[m-1][j].se.se <= te)
//           res += min(v2[m-1][j].se.se,te) - max(v2[m-1][j].se.fi,ts);
      }
      if(ma - mi > 0)
        res += ma - mi;
      cout << res << endl;
    }
  }
  return 0;
}

C++: #include<iostream>

using namespace std;

#define MMAX 100000
#define tMAX 12600
int main(){

	int N, M;
	int r;
	int t, n, m1, s;
	int q;
	int ts, te, m2;
	int num,cnt;
	int data[MMAX+1][tMAX+1];

	while (1){
		cin >> N >> M;
		if (N == 0 && M == 0) break;
		for (int i = 1; i <= M; i++){
			for (int j = 0; j <= tMAX; j++){
				data[i][j] = 0;
			}
		}
		cin >> r;
		for (int i = 0; i < r; i++){
			cin >> t >> n >> m1 >> s;
			if (s == 0) data[m1][t]--;
			else data[m1][t]++;
		}
		cin >> q;
		for (int i = 1; i <= M; i++){
			num = 0;
			for (int j = 0; j <= tMAX; j++){
				num += data[i][j];
				data[i][j] = num;
			}
		}
		for (int i = 0; i < q; i++){
			cin >> ts >> te >> m2;
			cnt = 0;
			for (int j = ts; j < te; j++){
				if (data[m2][j] >= 1) cnt++;
			}
			cout << cnt << 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]; 
      }
    }

    // ??????
    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;
    }
  }
}