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 <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;
            
            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
                    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;
            cout<<ret;
            
        }
    }
    
    return 0;
}

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

using namespace std;
 
typedef vector<int> V;
 
typedef struct{
    int t,n,m,s;
} Record;
 
int main(){
    int n,m,r,q;
   
    while(cin >> n >> m ,n + m){
	const int MAX = 1260-540;
 
	cin >> r;
	Record d[r];
	vector<V> v(m,V(MAX+1,-1)),cnt(m,V(MAX+1,0));
	int use[1001] = {0};
 
	for(int i = 0 ; i < r ; i++){
	    cin >> d[i].t >> d[i].n >> d[i].m >> d[i].s;
	    if(d[i].s){
		use[d[i].n-1] = d[i].t;
	    }
	    else{
		for(int j = use[d[i].n-1] ; j < d[i].t ; j++){
		    cnt[d[i].m-1][j-540] = 1;
		}
 
	    }
	}
 
	int ts,tt,sn;
	cin >> q;
	for(int i = 0 ; i < q ; i++){
	    cin >> ts >> tt >> sn;
 
	    sn--;
	    bool flg = true;
	    int ans = 0;
	    for(int i = ts ; i < tt ; i++){
		if(cnt[sn][i-540] != 0){
		    ans++;
		}
	    } 
	    cout << ans << endl;
	}
    }
    return 0;
}

C++: #include <cstdio>
#include <vector>
#define repeat(i, n) for (int i = 0; (i) < int(n); ++(i))
#define repeat_from(i, m, n) for (int i = (m); (i) < int(n); ++(i))
using namespace std;
template <typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); }
template <typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); }

constexpr int max_t = 1260;
int main() {
    while (true) {
        int n, m; scanf("%d%d", &n, &m);
        if (n == 0 and m == 0) break;
        auto login = vectors(m, max_t + 2, int());
        int r; scanf("%d", &r);
        while (r --) {
            int t, i, j, s; scanf("%d%d%d%d", &t, &i, &j, &s); -- i; -- j;
            login[j][t] += s ? +1 : -1;
        }
        repeat (j, m) {
            repeat (t, max_t + 1) {
                login[j][t + 1] += login[j][t];
            }
        }
        int q; scanf("%d", &q);
        while (q --) {
            int l, r, j; scanf("%d%d%d", &l, &r, &j); -- j;
            int result = 0;
            repeat_from (t, l, r) {
                result += bool(login[j][t]);
            }
            printf("%d\n", result);
        }
    }
    return 0;
}