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<map>
#include<algorithm>
#include<vector>

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

int N, M, r, q;
map<P, vector<P>> MAP;

int main() {
	while (1) {
		cin >> N >> M;
		if (N + M == 0)break;
		cin >> r;
		for (int i = 0; i < r; i++) {
			int t, n, m, s;
			cin >> t >> n >> m >> s;
			MAP[make_pair(n, m)].push_back(make_pair(t, s));
		}

		cin >> q;

		for (int i = 0; i < q; i++) {
			bool timetable[1261] = {};
			int ts, te, m;
			cin >> ts >> te >> m;
			int ans = 0;
			int ct = 0;
			int tmp = 0;

			for (int i = 0; i < N; i++) {
				for (int k = 0; k < MAP[make_pair(i + 1, m)].size(); k += 2) {
					int start = MAP[make_pair(i + 1, m)][k].first;
					int end = MAP[make_pair(i + 1, m)][k + 1].first;
					for (int l = start; l <= end; l++) {
						timetable[l] = true;
					}
				}
			}

			for (int j = ts; j <= te; j++) {
				if (timetable[j]) {
					tmp++;
				}
				else
				{
					ans += (tmp - 1 > 0 ? tmp - 1 : 0);
					tmp = 0;
				}
			}
			ans += (tmp - 1 > 0 ? tmp - 1 : 0);
			cout << ans << endl;
		}
		MAP.clear();
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#define INF 1 << 28
#define MAX_DATA 1 << 17
using namespace std;

typedef pair<int,int> P;

template <class T>
class SegmentTree
{
private :
    int n;
    vector<T> data;
public :
    void init(int);
    void update(int, int);
    int query(int, int, int, int, int);
    int size();
    T top();
};

template <class T>
void SegmentTree<T>::init (int n_) {
    n = 1;
    while (n < n_ + 1) n *= 2;
    data.resize(n * 2);
    for (int i = 0; i < data.size(); i++) data[i] = 0;
}

template <class T>
void SegmentTree<T>::update (int k_, int l_) {
    for (int i = k_; i <= 1260 - 540 && i < l_; i++) {
        int tmp_ = i + n - 1;
        data[tmp_] = 1;
        while (tmp_) {
            tmp_ = (tmp_ - 1) / 2;
            data[tmp_] = data[tmp_ * 2 + 1] + data[tmp_ * 2 + 2];
        }
    }
}

template <class T>
int SegmentTree<T>::query (int a_, int b_, int k_, int l_, int r_) {
    if (r_ <= a_ || b_ <= l_) return 0;

    if (a_ <= l_ && r_ <= b_) {
        return data[k_];
    }
    else {
        T vl = query(a_, b_, k_ * 2 + 1, l_, (l_ + r_) / 2);
        T vr = query(a_, b_, k_ * 2 + 2, (l_ + r_) / 2, r_);

        return (vl + vr);
    }
}

template <class T>
int SegmentTree<T>::size () {
    return n;
}

template <class T>
T SegmentTree<T>::top () {
    return data[0];
}

int main()
{
    int N, M;
    while (cin >> N >> M, (N || M)) {
        int R;
        cin >> R;

        vector<SegmentTree<int> > p(M + 1);
        for (int i = 0; i < p.size(); i++) {
            p[i].init(1260 - 540);
        }
        map<P,int> dat;
        for (int i = 0; i < R; i++) {
            int t, n, m, s;
            cin >> t >> n >> m >> s;

            t -= 540;
            if (s) {
                dat[P(n,m)] = t;
            } else {
                int tmp = dat[P(n,m)];
                auto ite = dat.find(P(n,m));
                dat.erase(ite);
                p[m].update(tmp, t);
            }
        }

        for (auto i : dat) {
            p[i.first.second].update(i.second, INF);
        }

        int Q;
        cin >> Q;
        for (int i = 0; i < Q; i++) {
            int ts, te, m;
            cin >> ts >> te >> m;
            ts -= 540;
            te -= 540;
            cout << p[m].query(ts, te, 0, 0, p[m].size()) << endl;
        }
    }



    return 0;
}

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


int main()
{
	int N,M;
	while(cin>>N>>M && N!=0){
		vector<int> PC(N+1,-1);
		vector<vector<pair<int,int> > > Stu(M+1);
		int r;
		cin>>r;
		for(int i=0;i<r;i++){
			int t,n,m,s;
			cin>>t>>n>>m>>s;
			if(s==0)
				Stu[m].push_back(make_pair(PC[n],t));
			else{
				PC[n]=t;
			}
		}
		int q;
		cin>>q;
		for(int i=0;i<q;i++){
			int s,e,m;
			cin>>s>>e>>m;
			sort(Stu[m].begin(),Stu[m].end());
			int ans=0;
			int time=s;
			for(int k=0;k<Stu[m].size();k++){
				if(Stu[m][k].second<time) continue;
				ans+=min(Stu[m][k].second,e)-max(time,Stu[m][k].first);
				time=min(Stu[m][k].second,e);
			}
			cout<<ans<<endl;
		}
	}
}