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>

using namespace std;

const int MaxN = 1001;
const int MaxM = 10001;

int N, M;

int main() {
  int count[MaxM];

  while(cin>>N>>M && !(N==0 && M==0)) {
    vector < vector< pair<int,int> > > logg(MaxM);
    int r;
    cin>>r;
    int t,n,m,s;
    for(int i=0; i<MaxM; i++) { // init
      count[i] = 0;
    }
    for(int i=0; i<r; i++) {
      cin>>t>>n>>m>>s;
      if(s == 1) { // login
	count[m]++;
	if(count[m] == 1) {
	  logg[m].push_back(make_pair(t,t));
	}
      }
      else { // logout
	count[m]--;
	if(count[m] == 0) {
	  logg[m].back().second = t;
	}
      }
    }
    int q;
    cin>>q;
    for(int i=0; i<q; i++) {
      int ts, te, m, ans = 0;
      cin>>ts>>te>>m;
      int ans1, ans2; // 4debug ans1は誤りらしい; エラーデータを弾けないから?
      for(int j=0; j<logg[m].size(); j++) {
	/*if(logg[m][j].first == logg[m][j].second) {
	  logg[m][j].second = te;
	}*/
	if(logg[m][j].first < te) {
	  ans1 = min(te, logg[m][j].second)-max(ts, logg[m][j].first);
	}
	else {
	  ans1 = 0;
	}
	ans2 = max(0, min(te,logg[m][j].second)-max(ts,logg[m][j].first));
	
        if(ans1!=ans2) {
	  cout<<"Q: "<<ts<<" "<<te<<endl;
	  cout<<"why: "<<min(te, logg[m][j].second)-max(ts, logg[m][j].first)<<endl;
	  cout<<"val: "<<logg[m][j].first<<" "<<logg[m][j].second<<endl;
	  cout<<"ans: "<<ans1<<" "<<ans2<<endl;
	}
	
        ans += ans2;
      }
      cout<<ans<<endl;
    }
  }
}

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

int main(){
    while(true){
        int N, M, r, q, t, n, m, s, ts, te, mm;
        vector<pair<int, pair<int, int> > > lg[10001];
        cin >> N >> M;
        if(!(N||M)) break;
        cin >> r;
        for(int i=0;i<r;++i){
            cin >> t >> n >> mm >> s;
            lg[mm].push_back(make_pair(t, make_pair(n, s)));
        }
        cin >> q;
        for(int i=0;i<q;++i){
            set<int> pc;
            int cnt=0;
            int start=0;
            cin >> ts >> te >> m;
            for(int j=0;j<lg[m].size();++j){
                if(lg[m][j].second.second == 1){
                    pc.insert(lg[m][j].second.first);
                }else{
                    pc.erase(lg[m][j].second.first);
                }
                if(lg[m][j].first < ts){
                    if(!pc.empty()){
                        start = ts;
                    }else{
                        start = 0;
                    }
                }else if(ts <= lg[m][j].first && lg[m][j].first <= te){
                    if(!pc.empty() && start==0){
                        start = lg[m][j].first;
                    }else if(pc.empty() && start!=0){
                        cnt += lg[m][j].first-start;
                        start = 0;
                    }
                }else if(lg[m][j].first > te){
                    if(start!=0) cnt += te-start;
                    break;
                }
            }
            cout << cnt << endl;
        }
    }
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<map>
#include<queue>
using namespace std;
struct data{
    int t,s;
    data(int a,int b):t(a),s(b){}
    data(){}
};
int main(){
    int N,M;
    while(cin>>N>>M,N||M){
        int r;cin>>r;
        vector<data>V[10000];
        while(r--){
            int t,n,m,s;
            cin>>t>>n>>m>>s;
            m--;
            V[m].push_back(data(t,s));
        }
        //for(int i=0;i<M;i++)cout<<i<<":"<<V[i].size()<<endl;
        int q;
        cin>>q;
        while(q--){
            int ts,te,m;
            cin>>ts>>te>>m;
            m--;
            int imoss[2000]={0};
            //cout<<V[m].size()<<endl;
            for(int i=0;i<V[m].size();i++){
                data &d=V[m][i];
                if(d.s)imoss[d.t]++;
                else imoss[d.t]--;
                //cout<<d.t<<" "<<d.s<<endl;
            }
            for(int i=1;i<=1260;i++)imoss[i]+=imoss[i-1];
            int cnt=0;
            for(int i=ts;i<te;i++)if(imoss[i])cnt++;
            cout<<cnt<<endl;
        }
    }
    return 0;
}

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

int main () {
	int N, M;
	while (cin >> N >> M, N || M) {
		bool table[M + 1][1260];
		int lastin[N + 1];
		int r;
		memset(table, 0, sizeof(table));
		cin >> r;
		for (int i = 0; i < r; i++) {
			int t, n, m, s;
			cin >> t >> n >> m >> s;
			if (s) {
				lastin[n] = t;
			}
			else {
				fill(table[m] + lastin[n], table[m] + t, true);
			}
		}
		int q;
		cin >> q;
		for (int i = 0; i < q; i++) {
			int s, e, m;
			cin >> s >> e >> m;
			cout << count(table[m] + s, table[m] + e, true) << endl;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<stack>
using namespace std;
struct data{int l,r;};
int N,M,r,q;
vector<data> g[10001];

void init(){
  for(int i=0;i<10001;i++)g[i].clear();
}

int main(){
  while(1){
    cin>>N>>M;
    if(N==0&&M==0)break;
    init();
    stack<int> st[10001];
    cin>>r;
    for(int i=0;i<r;i++){
      int t,n,m,s;
      cin>>t>>n>>m>>s;
      if(s){
	st[m].push(t);
      }else{
	int x=st[m].top();st[m].pop();
	if(st[m].empty())g[m].push_back((data){x,t});
      }
    }
    cin>>q;
    for(int i=0;i<q;i++){
      int a,b,m,sum=0;
      cin>>a>>b>>m;
      for(int i=0;i<(int)g[m].size();i++){
	data d=g[m][i];
	if(d.r<=a||b<=d.l)continue;
	sum+=(min(d.r,b)-max(d.l,a));
      }
      cout<<sum<<endl;
    }
  }
}