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 <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <tuple>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

typedef long long LL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define DECIM8  fixed<<setprecision(8) 
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

using namespace std;
int usepc[10010][1310];
int main(void)
{
  for(;;){
    REP(i,10010) REP(j,1310){
      usepc[i][j]=0;
    }
    int N,M;
    cin >> N >> M;
    if(!N&&!M) return 0;
    int r;
    cin >> r;
    REP(i,r){
      int t,n,m,s;
      cin >> t >> n >> m >> s;
      usepc[m][t]+=1-2*s;
    }
    REP(i,M+1) REP(j,1300){
      usepc[i][j+1]+=usepc[i][j];
    }
    REP(i,M+1) REP(j,1300){
      if(usepc[i][j+1]) usepc[i][j+1]=usepc[i][j]+1;
      else usepc[i][j+1]=usepc[i][j];
    }
    int q;
    cin >> q;
    REP(i,q){
      int ts,te,m;
      cin >> ts >> te >> m;
      cout << usepc[m][te-1]-usepc[m][ts-1] << endl;
    }
  }
}

C++: #include <iostream>
#include <stack>
#include <queue>

using namespace std;

int main()
{
    bool flagflag=true;
    int N,M;
    while(cin>>N>>M){
        if(N==0&&M==0)break;
        
        int r;
        cin>>r;
        int data[1000][4];
        for(int i=0; i<r; i++){
            int tt,nn,mm,ss;
            cin>>tt>>nn>>mm>>ss;
            data[i][0]=tt;
            data[i][1]=nn;
            data[i][2]=mm;
            data[i][3]=ss;
            
        }
        
        int q;
        cin>>q;
        for(int roop=0; roop<q; roop++){
            int ts,te,mm;
            cin>>ts>>te>>mm;
            int start=ts;
            int ret=0;
            bool in_flag=false;
            
            queue<int> qu;
            
            for(int i=0; i<r; i++){
                if(data[i][0]>te)break;
                if(data[i][2]==mm){//dataが対象人物
                    in_flag=true;
                    if(data[i][3]==1){//ログインなら
                        if(qu.empty()){
                            start=data[i][0];
                            if(start<ts)start=ts;
                            

                        }
                        qu.push(data[i][1]);
                    }else{//ログアウトなら
                        int qusize=(int)qu.size();
                        for(int j=0; j<qusize; j++){
                            int pc = qu.front();
                            qu.pop();
                            if(pc==data[i][1])break;
                            else qu.push(pc);
                        }
                        int end = data[i][0];
                        if(qu.empty()){
                            if(end>te)end=te;
                            if(start<end)ret+=end-start;
                        }
                    }

                }
            }
            
            if(!qu.empty()){
                if(start<te)ret+=te-start;
            }
            
            if(flagflag)flagflag=false;
            else cout<<endl;
            if(in_flag)cout<<ret;
            else cout<<0;
            
        }
    }
    
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
int main(){
  while (1){
    int N, M;
    cin >> N >> M;
    if (N == 0 && M == 0){
      break;
    }
    vector<vector<pair<int, int>>> R(M);
    vector<int> cnt(M, 0);
    int r;
    cin >> r;
    for (int i = 0; i < r; i++){
      int t, n, m, s;
      cin >> t >> n >> m >> s;
      m--;
      if (s == 1){
        if (cnt[m] == 0){
          R[m].push_back(make_pair(t, -1));
        }
        cnt[m]++;
      }
      if (s == 0){
        cnt[m]--;
        if (cnt[m] == 0){
          R[m].back().second = t;
        }
      }
    }
    int q;
    cin >> q;
    for (int i = 0; i < q; i++){
      int ts, te, m;
      cin >> ts >> te >> m;
      m--;
      int ans = 0;
      int cnt = R[m].size();
      for (int j = 0; j < cnt; j++){
        int s = R[m][j].first;
        int e = R[m][j].second;
        ans += max(min(te, e) - max(ts, s), 0);
      }
      cout << ans << endl;
    }
  }
}