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<vector>
#include<map>
#include<cassert>
#include<algorithm>
using namespace std;

struct Record{
  int s;
  int t;
  int n;
  int m;
  Record(int s,int t,int n,int m) : s(s), t(t), n(n), m(m) {;}
};

bool operator<(const Record &l, const Record &r) {
  return (r.t != l.t) ? l.t < r.t : l.m < r.m;
}

int main() {
  int N,M,r,q;
  while(cin>>N>>M, N|M) {
    cin>>r;
    int t,n,m,s;
    vector<Record> in;
    for(int i=0; i<r; ++i) {
      cin>>t>>n>>m>>s;
      in.push_back(Record(s,t,n,m));
    }
    cin>>q;
    int ts,te;
    sort(in.begin(), in.end());
    for(int i=0; i<q; ++i) {
      cin>>ts>>te>>m;
      int ans = 0,use = 0,start = -1,fans;
      vector<pair<int,int> > v;
      for(int j=0; j<in.size(); ++j) {
	if(in[j].m != m) continue;
	if(in[j].s == 1) {
	  if(use == 0 && start == -1)
	    start = in[j].t;
	  use++;
	}
	if(use > 0 && in[j].s == 0) {
	  use--;
	  if(use == 0) {
	    ans += in[j].t - start;
	    v.push_back(pair<int,int>(start,in[j].t));
	    start = -1;
	  }
	}
      }
      assert(use == 0);
      fans = 0;
      for(int j=0; j<v.size(); ++j) {
	if(v[j].first >= te || v[j].second <= ts) continue;
	if(v[j].first <= ts && v[j].second >= te) {
	  fans += te - ts;
	}else if(v[j].first <= ts) {
	  fans += v[j].second - ts;
	}else if(v[j].second >= te) {
	  fans += te - v[j].first;
	}else{
	  fans += v[j].second - v[j].first;
	}
      }
      cout<<fans<<endl;
    }
  }
}

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

struct S {
	int t, n, m, s;
};
vector<S> rec;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int N, M, r, q;
	while(cin >> N >> M, N | M) {
		cin >> r;
		rec.clear();

		for(int i = 0; i < r; i++) {
			int t, n, m, s;
			cin >> t >> n >> m >> s;
			rec.push_back(S{ t, n, m, s });
		}

		cin >> q;
		while(q--) {
			int ts, te, m;
			cin >> ts >> te >> m;
			int s = ts, c = 0;
			int sum = 0;
			for(int i = 0; i < r; i++) {
				if(rec[i].m != m) continue;
				if(rec[i].t > te) break;
				if(rec[i].s == 0) {
					c--;
					if(c == 0) {
						sum += rec[i].t - s;
					}
				}
				else {
					if(c == 0 && ts <= rec[i].t) {
						s = rec[i].t;
					}
					c++;
				}
			}
			if(c) {
				sum += te - s;
			}
			cout << sum << endl;
		}
	}
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<tuple>

using namespace std;
typedef pair<int, int> pii;

int main(){

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

        int a[M][1270];
        for(int i=0; i<M; i++){
            for(int j=0; j<2000; j++){
                a[i][j]=0;
            }
        }
        for(int i=0; i<r; i++){
            int t, n, m, s;
            cin>> t>> n>> m>> s;
            n--; m--;
            if(s){
                a[m][t]+=1;
            }else{
                a[m][t]-=1;
            }
        }
        for(int i=0; i<M; i++){
            for(int j=1; j<1270; j++){
                a[i][j]+=a[i][j-1];
            }
        }

        int Q;
        cin>> Q;
        for(int i=0; i<Q; i++){
            int s, e, m;
            cin>> s>> e>> m;
            m--;
            int k=0;
            for(int j=s; j<e; j++){
                k+=(a[m][j]>0);
            }
            cout<< k<< endl;
        }
    }

    return 0;
}

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

struct Record{

  int s_cnt,e_cnt;
  int s[1000],e[1000];
  
};

int main(){
  
  int N,M;
  int r,q,t,n,m,s;
  int t_s,t_g;
  int table[1000];
  
  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[student[m].s_cnt]=t;
	student[m].s_cnt++;
      }else{
	student[m].e[student[m].e_cnt]=t;
	student[m].e_cnt++;
      }
    }
    
    cin >>q;
    for(int i=0 ; i < q ; i++){
      cin >>t_s>>t_g>>m;
      for(int j=0 ; j < 1000 ; j++)table[j]=0;
      for(int j=0 ; j < student[m].s_cnt ; j++){
	for(int k=student[m].s[j]-540 ; k < student[m].e[j]-540 ; k++){
	  table[k]=1;
	}
      }
      int sum=0;
      for(int j=t_s-540 ; j < t_g-540  ; j++)sum+=table[j];
      cout <<sum<<endl;
    }
    
  }
  
  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
int ta[1100][2100];//時間iのときのPCjの中に利用者を入れる
int info[1100][4];
int main(){
	int n,m,r,q;
	while(true){
	cin>>n>>m;
	if(n==0&&m==0)break;
	cin>>r;
	for(int i=0;i<2100;i++)for(int j=0;j<1100;j++)ta[j][i]=0;
	for(int i=0;i<1100;i++)for(int j=0;j<4;j++)info[i][j]=0;
	for(int i=0;i<r;i++){
	for(int j=0;j<4;j++)cin>>info[i][j];
	}
	for(int i=0;i<r;i++){
	int time=info[i][0],pc=info[i][1],p=info[i][2],f=info[i][3];
	if(f!=0){
		ta[pc][time]=p;
	}
	else ta[pc][time]=-p;
	}
	for(int i=0;i<1000;i++){
		for(int j=0;j<1999;j++){
		ta[i][j+1]+=ta[i][j];
		}
	}
	cin>>q;
for(int countfor=0;countfor<q;countfor++){
int ts,te,m,ans=0;
bool f=0;
cin>>ts>>te>>m;
for(int i=ts;i<te;i++){
	f=0;
	for(int j=0;j<=n;j++){
	if(ta[j][i]==m)f=1;
	}
	if(f){ans++;}
}
cout<<ans<<endl;
}
}
	return 0;
}