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 <string>
#include <algorithm>
#include <cstring>
#include <map>
#include <queue>
#include <stack>
#include <set>
#include <functional>
#include <sstream>
#include <complex>
#include <climits>
using namespace std;

#define REP(i,a,n) for(int i=(a);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define mp make_pair
#define all(x) x.begin(),x.end()
#define EPS 1e-8

typedef struct _kiroku{
	int t,n,m,s;
} kiroku;

kiroku kiro[1024];

int main(){
	int n,m,r,q,ts,te,mm;
	while(scanf("%d%d",&n,&m),n|m){
		scanf("%d",&r);
		rep(i,r)scanf("%d%d%d%d",&kiro[i].t, &kiro[i].n, &kiro[i].m, &kiro[i].s);
		
		scanf("%d",&q);
		rep(i,q){
			scanf("%d%d%d",&ts,&te,&mm);
			int sum = 0;
			int start = 0;
			int cnt = 0;
			for(int i=0; i<r; i++)if( kiro[i].m==mm ){
				if( cnt==0 ){	 //init
					start = kiro[i].t;
					cnt++;
				}else{
					if( kiro[i].s==1 )cnt++;
					else              cnt--;
					if( cnt==0 ){
						//printf("%d - %d = %d\n",kiro[i].t,max(ts,start),kiro[i].t-start);
						if( kiro[i].t<ts )continue;
						if( min(te,kiro[i].t)<max(ts,start) )break;
						sum += (min(te,kiro[i].t)-max(ts,start));
					}
				}
			}
			printf("%d\n",sum);
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int MAX_M = 10000;

int N, M;
int r, q;
int use[MAX_M][1261];

int main() {
	while (true) {
		cin >> N >> M;
		if (N == 0) {
			break;
		}
		//cout << "check1" << endl;
		
		int usePc[M+1]; // 使用しているPCの数
		int useLastStart[M+1]; // 最後に使用し始めた時間
		//int useTime[M+1]; // 使用時間
		memset(use, 0, sizeof(use));
		memset(usePc, 0, sizeof(usePc));
		memset(useLastStart, 0, sizeof(useLastStart));
		//memset(useTime, 0, sizeof(useTime));
		
		
		cin >> r;
		for (int i = 0; i < r; i++) {
			int t, n, m, s;
			cin >> t >> n >> m >> s;
			if (s == 1) {
				// ログイン
				if (usePc[m] == 0) {
					useLastStart[m] = t;
				}
				usePc[m]++;
			} else {
				// ログアウト
				usePc[m]--;
				if (usePc[m] == 0) {
					for (int j = t - 1; j >= useLastStart[m]; j--) {
						use[m][j] = 1;
					}
				}
			}
		}
		//cout << "check2" << endl;
		cin >> q;
		for (int i = 0; i < q; i++) {
			int ts, te, m;
			int ans = 0;
			cin >> ts >> te >> m;
			
			for (int j = ts; j < te; j++) {
				if (use[m][j] == 1) {
					ans++;
				}
			}
			cout << ans << endl;
		}
	}
	
	return 0;
}

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

using namespace std;

#define all(c) (c).begin(), (c).end()
#define loop(i,a,b) for(int i=a; i<int(b); i++)
#define rep(i,b) loop(i,0,b)

struct event{
    int pc, time;
    bool login;
    event(int pc, int time, bool login)
        : pc(pc), time(time), login(login){}
};

typedef vector<event> ve;
typedef vector<ve> vve;

vve es;

inline pair<int, int> intersection(int l1, int r1, int l2, int r2){
    int l = max(l1, l2), r = min(r1, r2);
    return make_pair(l, r);
}

int main(){
    int N, M;
    while (cin >> N >> M && N | M){
        es.assign(M + 1, {});
        int r; cin >> r;
        rep(i, r){
            int t, n, m, s;
            cin >> t >> n >> m >> s;
            es[m].emplace_back(n, t, s);
        }
        rep(i, M + 1)sort(all(es[i]), [](const event & a, const event& b){
            return a.time < b.time;
        });
        int q; cin >> q;
        rep(i, q){
            bool use[1260] = {};
            int ts, te, m; cin >> ts >> te >> m;
            int ans = 0;
            auto & e = es[m];
            rep(i, e.size()){
                if (e[i].login){
                    int j = i+1;
                    while (e[i].pc != e[j].pc){
                        j++;
                    }
                    auto p = intersection(ts, te, e[i].time, e[j].time);
                    loop(k, p.first, p.second){
                        use[k] = true;
                    }
                }
            }
            rep(i, 1260)ans += use[i];
            cout << ans << endl;
        }
    }
}

C++: #include<iostream>
 
using namespace std;
 
#define MMAX 10000
#define tMAX (60*24)

int main(void){
 
    int N, M;
    int r;
    int t, n, m1, s;
    int q;
    int ts, te, m2;
    int num,cnt;
    int data[MMAX+1][tMAX+1];
 
    while (cin >> N >> M){
        if (N == 0 && M == 0) break;
        for (int i = 0; i <= MMAX; i++){
            for (int j = 0; j <= tMAX; j++){
                data[i][j] = 0;
            }
        }
        cin >> r;
		
        for (int i = 0; i < r; i++){
            cin >> t >> n >> m1 >> s;
            if (s == 0) data[m1][t]--;
            else data[m1][t]++;
        }
		
        for (int i = 1; i <= M; i++){
            num = 0;
            for (int j = 0; j <= tMAX; j++){
                num += data[i][j];
                data[i][j] = num;
            }
        }
		cin>>q;
        for (int i = 0; i < q; i++){
            cin >> ts >> te >> m2;
            cnt = 0;
            for (int j = ts; j < te; j++){
                if (data[m2][j] >= 1) cnt++;
            }
			return 0;
            cout << cnt << endl;
        }
    }
    return 0;
}