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 <cstring>
#include <algorithm>

#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)

using namespace std;
typedef long long ll;

int cnt[10005][1500];

int main()
{
    int N,M;
    while(cin >> N >> M) {
        if(N == 0 && M == 0) break;
        
        int ptime[1005];
        memset(ptime,0,sizeof(ptime));

        int r;
        cin >> r;
        
        vector<pair<pair<int,int>,int> > v;
        rep(i,r) {
            int t,n,m,s;
            cin >> t >> n >> m >> s;

            if(s == 1) {
                ptime[n] = t;
            }
            else {
                pair<int,int> p = make_pair(ptime[n],t);
                v.push_back(make_pair(p,m));
            }
        }

        memset(cnt,0,sizeof(cnt));
        rep(i,v.size()) {
            int start = v[i].first.first;
            int end = v[i].first.second;
            int num = v[i].second;

            cnt[num][start]++;
            cnt[num][end+1]--;
        }

        rep(i,M+1) {
            REP(j,540,1500) {
                cnt[i][j+1] += cnt[i][j];
            }
        }

        vector<pair<pair<int,int>,int> > res;
        rep(i,M+1) {
            REP(j,540,1500) {
                if(cnt[i][j] > 0) {
                    int s = j;
                    while(cnt[i][j+1] > 0) {
                        j++;
                    }
                    
                    pair<int,int> p = make_pair(s,j);
                    res.push_back(make_pair(p,i));
                }
            }
        }


        int q;
        cin >> q;

        rep(i,q) {
            int s,t,m;
            cin >> s >> t >> m;
            
            int ans = 0;
            rep(j,res.size()) {
                int start = res[j].first.first;
                int end = res[j].first.second;
                int num = res[j].second;
                
                if(num != m) continue;

                if(end < s || t < start) continue;
                else if(start <= s && t <= end) {
                    ans += t - s;
                }
                else if(s < start && t <= end) {
                    ans += t - start;
                }
                else if(start <= s && end < t) {
                    ans += end - s;
                }
                else if(s < start && end < t) {
                    ans += end - start;
                }
            }
            cout << ans << endl;
        }
    }

    return 0;
}

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

using namespace std;

int log[10001][1261];
int state[1001];

int main(){
    int n,m,r,q;

    while(cin >> n >> m){
        if((n|m) == 0) break;
        memset(log, -1, sizeof(log));
        memset(state, -1, sizeof(state));
        cin >> r;
        
        int t, _n, _m, s, ts, te, mq, tmp;
        for(int i=0;i<r;i++){
            cin >> t >> _n >> _m >> s;
            if(s){//login
                state[_n] = t;
            }else{//logout
                for(int j=state[_n];j<=t;j++){
                    log[_m][j] = t;
                }
            }
        }

        cin >> q;
        int ret;
        for(int i=0;i<q;i++){
            ret = 0;
            cin >> ts >> te >> mq;
            tmp = ts;
            while(tmp < te){
                if(log[mq][tmp] != -1 && tmp != log[mq][tmp]){
                    ret += min(te, log[mq][tmp]) - tmp;
                    tmp = min(te, log[mq][tmp]);
                }else{
                    tmp++;
                }
            }
            cout << ret << endl;
        }
    }
}

C++: #include<iostream>
#include<string>
using namespace std;
int s[1000][4];
int main(){
	int n,m;
	while(true){
	cin>>n>>m;
	if(n==0&&m==0)
		break;
	int r;
	cin>>r;
	for(int i=0;i<r;i++)
		for(int j=0;j<4;j++)
		    cin>>s[i][j];
	int q;
	cin>>q;
	int bef,aft,m;
	for(int u=0;u<q;u++){
		cin>>bef>>aft>>m;
		int ans=0;
		int in=0;
		for(int i=0;i<r;i++){
			if(s[i][0]<bef&&s[i][2]==m){
				if(s[i][3]==1)
					in++;
				if(s[i][3]==0)
					in--;
			}
		}
		for(int time=bef;time<aft;time++){
			for(int i=0;i<r;i++){
				if(s[i][0]==time&&s[i][2]==m){
					if(s[i][3]==1)
						in++;
					if(s[i][3]==0)
						in--;
				}
			}
			if(in>0)
				ans++;
		}
		cout<<ans<<endl;
	}
	}
	return 0;
}

C++: #include <iostream>

using namespace std;
#define max 1260-540

bool times[10000][max+1];

int main(void){
	int N,M,r,q;
	while(cin >> N  >> M, N|M){
		for(int i=0;i<M;i++)
			for(int j=0;j<=max;j++)
				times[i][j]=false;

		cin >> r;
		int start[1001];
		for(int i=0;i<r;i++){
			int t,n,m,s;
			cin >> t >> n >> m >> s;
			if(s)
				start[n]=t-520;
			else{
				for(int k=start[n];k<t-520;k++)
					times[m][k]=true;
			}
		}
		cin >> q;
		for(int i=0;i<q;i++){
			int ts,te,m;
			cin >> ts >> te >> m;
			int num=0;
			for(int i=ts-520;i<te-520;i++){
				if(times[m][i])
					num++;
			}
			cout << num << endl;
		}
	}

	return 0;
}