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 <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <string>
#include <stack>
#include <queue>
#include <cmath>
#include <cstdio>
#include <istream>
#include <sstream>
#include <iomanip>
using namespace std;

typedef ostringstream oss;
typedef istringstream iss;

typedef vector<int> vi;
typedef vector< vi > vvi;

const int MIN_TIME = 540;
const int MAX_TIME = 1260;


int main(void) {
	int pcNum, stuNum;
	while (cin >> pcNum >> stuNum, pcNum) {
		vector< vvi > recs(stuNum, vvi(pcNum, vi(MAX_TIME - MIN_TIME + 1, 0)));

		int recNum, queNum;
		cin >> recNum;
		for (int ri = 0; ri < recNum; ri++) {
			int time, pc, stu, type;
			cin >> time >> pc >> stu >> type;
			pc--; stu--;
			time -= MIN_TIME;
			if (type) {
				fill(recs[stu][pc].begin() + time, recs[stu][pc].end(), 1);
			}else {
				fill(recs[stu][pc].begin() + time, recs[stu][pc].end(), 0);
			}
		}

		vvi recsSum(stuNum, vi(MAX_TIME - MIN_TIME + 1, 0));
		for (int si = 0; si < stuNum; si++) {
			for (int pi = 0; pi < pcNum; pi++) {
				for (int ti = MAX_TIME - MIN_TIME; ti >= 0; ti--) {
					recsSum[si][ti] = max(recsSum[si][ti], recs[si][pi][ti]);
				}
			}
		}

		cin >> queNum;
		for (int qi = 0; qi < queNum; qi++) {
			int start, end, stu;
			cin >> start >> end >> stu;
			stu--;
			start -= MIN_TIME; end -= MIN_TIME;

			int time = 0;
			for (int ti = start; ti < end; ti++) {
				time += recsSum[stu][ti];
			}

			cout << time << endl;
		}
	}

	return 0;
}

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

struct D{
  int t,s;
};

vector<vector<D>> data;
void init(){
  data.clear();
}
int q;
void print(){
  for(int i=0;i<data.size();i++){
    cout<<"m="<<i<<":";
    for(int j=0;j+1<data[i].size();j+=2){
      cout<<"("<<data[i][j].t<<"-"<<data[i][j+1].t<<")";
    }cout<<endl;
  }
}
bool input(){
  int n,m;
  cin>>n>>m;
  if(n==0&&m==0)return false;
  int r;
  cin>>r;
  data.resize(m+10);
  for(int i=0;i<r;i++){
    int t,n,m,s;
    cin>>t>>n>>m>>s;
    if(data[m].size()==0 || data[m][data[m].size()-1].s!=s){
      data[m].push_back(D{t,s});
    }else if(data[m][data[m].size()-1].s==0){
      int pre_t = data[m][data[m].size()-1].t;
      data[m][data[m].size()-1].t = max(pre_t,t);
    }
  }
  cin>>q;
}
int solve(){
  int s,e,m;
  cin>>s>>e>>m;
  //cout<<s<<" "<<e<<" "<<m<<endl;
  const vector<D> l = data[m];
  int ans = 0;
  //cout<<"cal"<<endl;
  for(int i=0;i<(int)l.size()-1;i++){
    if(l[i].s==1&&(s<l[i+1].t)&&l[i].t<=e){
      ans += l[i+1].t - max(s,l[i].t);
      if(e<=l[i+1].t){
        ans -= l[i+1].t - e;
      }
    }
  }
  return ans;
}

int main(){
  while(init(),input()){
    //print();
    for(int i=0;i<q;i++){
      int ans = solve();
      cout<<ans<<endl;
    }
  }
}

C++: #include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <climits>
#include <ctime>
#include <cassert>
using namespace std;

#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define all(v) begin(v), end(v)
#define pb(a) push_back(a)
#define fr first
#define sc second
#define INF 2000000000
#define int long long int

#define X real()
#define Y imag()
#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) ( EQ((a).X, (b).X) && EQ((a).Y, (b).Y) )
#define LE(n, m) ((n) < (m) + EPS)
#define LEQ(n, m) ((n) <= (m) + EPS)
#define GE(n, m) ((n) + EPS > (m))
#define GEQ(n, m) ((n) + EPS >= (m))

typedef vector<int> VI;
typedef vector<VI> MAT;
typedef pair<int, int> pii;
typedef long long ll;

typedef complex<double> P;
typedef pair<P, P> L;
typedef pair<P, double> C;

int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};
int const MOD = 1000000007;

namespace std {
    bool operator<(const P& a, const P& b) {
        return a.X != b.X ? a.X < b.X : a.Y < b.Y;
    }
}

int calc(int s, int e, int ts, int te) {
    int x = min(e, te) - max(s, ts);
    if(x < 0) x = 0; return x;
}

vector<pii> v[10010];
int logs[10010][1010];
int ruiseki[1010];
signed main() {
    int N, M;
    while(cin >> N >> M) {
        if(N == 0 && M == 0) break;
        memset(logs, 0, sizeof(logs));
        int r, t, n, m, s; cin >> r;
        rep(i,0,r) {
            cin >> t >> n >> m >> s;
            t -= 540;
            m--;
            if(s == 0) v[m].pb(pii(logs[m][n], t));
            else logs[m][n] = t;
        }

        int q; cin >> q;
        rep(i,0,q) {
            int ts, te, mm; cin >> ts >> te >> mm;
            ts -= 540; te -= 540;
            mm--;

            memset(ruiseki, 0, sizeof(ruiseki));
            rep(j,0,v[mm].size()) {
                ruiseki[ v[mm][j].fr     ]++;
                ruiseki[ v[mm][j].sc + 1 ]--;
            }
            int ans = 0;
            rep(j,1,1000) {
                ruiseki[j] += ruiseki[j-1];
                if(ruiseki[j] && ruiseki[j-1] && ts < j && j <= te) ans++;
            }
            cout << ans << endl;
        }
    }
    return 0;
}