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 <bits/stdc++.h>

using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N, M;
    while (true)
    {
        cin >> N >> M;
        if (N == 0)
            break;
        int r;
        cin >> r;
        VVI v(M, vector<int>(1000, 0));
        for (int i = 0; i < r; i++)
        {
            int t, n, m, s;
            cin >> t >> n >> m >> s;
            t -= 540;
            m--;
            if (s)
                v[m][t]++;
            else
                v[m][t]--;
        }
        for (int i = 0; i < M; i++)
        {
            for (int j = 1; j <= 720; j++)
            {
                v[i][j] += v[i][j - 1];
            }
        }
        int q;
        cin >> q;
        for (int i = 0; i < q; i++)
        {
            int ts, te, m;
            cin >> ts >> te >> m;
            ts -= 540;
            te -= 540;
            m--;
            int res = 0;
            for (int j = ts; j < te; j++)
                if (v[m][j])
                    res++;
            cout << res << endl;
        }
    }
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen

#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> P;
bool tt[1300];
vector<P> student[10005];
struct LOG{
	int t, n, m, s;
};
	
int main()
{
//	cut here before submit 
//	freopen ("testcase.ALLR", "r", stdin );
	int N, M;
	while (scanf ("%d %d", &N, &M ), N, M ){
		rep (i, M ) student[i].clear();
		int r;
		scanf ("%d", &r );

		LOG log[r];
		rep (i, r ){
			int t, n, m, s;
			scanf ("%d %d %d %d", &t, &n, &m, &s );
			n--;m--;
			log[i].t = t, log[i].n = n, log[i].m = m, log[i].s = s;
		} // end rep

		rep (i, r ){
			if (log[i].s == 0 ) continue;
			int cn = log[i].n, cm = log[i].m;
			int st = log[i].t;
			for (int j = i+1; j < r; j++ ){
				if (log[j].n == cn && log[j].m == cm && log[j].s == 0 ){
					int et = log[j].t;
					student[cm].push_back (P (st, et ) );
					break;
				} // end if
			} // end for
		} // end rep

		int q;
		scanf ("%d", &q );
		vector<int> ans (q, 0 );

		rep (i, q ){
			int ts, te, m;
			scanf ("%d %d %d", &ts, &te, &m );
			m--;
			memset (tt, false, sizeof (tt ) );
			if (!student[m].empty() ){
				rep (j, student[m].size() ){
					for (int t = student[m][j].first; t < student[m][j].second; t++ ){
						tt[t] = true;
					} // end for
				} // end rep
			} // end if

			int res = 0;
			for (int t = ts; t < te; t++ ){
				if (tt[t] ) res++;
			} // end if
			ans[i] = res;
		} // end rep
		rep (i, q ){
			printf ("%d\n", ans[i] );
		} // end rep
			
	} // end loop
		
	return 0;
}

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;
                            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;
}