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 <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <climits>
#include <ctime>
#include <cassert>
using namespace std;

#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define all(v) begin(v), end(v)
#define pb(a) push_back(a)
#define fr first
#define sc second
#define INF 2000000000
#define int long long int

#define X real()
#define Y imag()
#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) ( EQ((a).X, (b).X) && EQ((a).Y, (b).Y) )
#define LE(n, m) ((n) < (m) + EPS)
#define LEQ(n, m) ((n) <= (m) + EPS)
#define GE(n, m) ((n) + EPS > (m))
#define GEQ(n, m) ((n) + EPS >= (m))

typedef vector<int> VI;
typedef vector<VI> MAT;
typedef pair<int, int> pii;
typedef long long ll;

typedef complex<double> P;
typedef pair<P, P> L;
typedef pair<P, double> C;

int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};
int const MOD = 1000000007;

namespace std {
    bool operator<(const P& a, const P& b) {
        return a.X != b.X ? a.X < b.X : a.Y < b.Y;
    }
}

int calc(int s, int e, int ts, int te) {
    int x = min(e, te) - max(s, ts);
    if(x < 0) x = 0; return x;
}

map< int, map<int, int> > logs;
int ruiseki[1010];
signed main() {
    int N, M;
    while(cin >> N >> M) {
        if(N == 0 && M == 0) break;
        vector<pii> v[10010];
        logs.clear();
        int r, t, n, m, s; cin >> r;
        rep(i,0,r) {
            cin >> t >> n >> m >> s;
            t -= 540;
            m--;
            if(s == 0) v[m].pb(pii(logs[m][n], t));
            else logs[m][n] = t;
        }

        int q; cin >> q;
        rep(i,0,q) {
            int ts, te, mm; cin >> ts >> te >> mm;
            ts -= 540; te -= 540;
            mm--;

            memset(ruiseki, 0, sizeof(ruiseki));
            rep(j,0,v[mm].size()) {
                ruiseki[ v[mm][j].fr     ]++;
                ruiseki[ v[mm][j].sc + 1 ]--;
            }
            int ans = 0;
            rep(j,1,1000) {
                ruiseki[j] += ruiseki[j-1];
                if(ruiseki[j] && ruiseki[j-1] && ts < j && j <= te) ans++;
            }
            cout << ans << endl;
        }
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
int main(){
    int N,M;
    cin>>N>>M;
    int r;
    cin>>r;
    vector<int> t(r),n(r),m(r),s(r);
    for(int i=0;i<r;i++){
        cin>>t[i]>>n[i]>>m[i]>>s[i];
    }
    int q;
    cin>>q;
    vector<int> ts(q),te(q),qm(q);
    for(int i=0;i<q;i++){
        cin>>ts[i]>>te[i]>>qm[i];
    }
    for(int i=0;i<q;i++){
        int sum=0;
        int start=0;
        for(int j=0;j<r;j++){
            if(m[j]==qm[i]){
                if(s[j]==1){
                    start=t[j];
                }else{
                    sum+=min(t[j],te[i])-max(ts[i],start);
                }
            }
        }
        cout<<sum<<endl;
    }
}

C++: //Analyzing Login/Logout Records
#include<bits/stdc++.h>
using namespace std;

int main(){
  int N, M;
  while(cin>>N>>M, !(N==0&&M==0)){
    int pc[N][721], st[M][721], r;
    memset(pc, 0, sizeof(pc)); memset(st, 0, sizeof(st));
    cin>>r;
    while(r--){
      int t, n, m, s;
      cin>>t>>n>>m>>s;
      pc[n-1][t-540]=m;
      if(s==0){
	st[m-1][t-540]=1;
	t--;
	while(true){
	  st[m-1][t-540]=1;
	  if(pc[n-1][t-540]==m || t-540==-1)break;
	  t--;
	}
      }
    }
    int q;
    cin>>q;
    while(q--){
      int ts, te, m;
      cin>>ts>>te>>m;
      int cnt=0;
      bool flag=false;
      for(int i=ts-540; i<=te-540; i++){
	if(st[m-1][i]==1 && flag)
	  cnt++;
	if(st[m-1][i]==1)flag=true;
	else flag=false;
      }
      cout<<cnt<<endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<cstring>
#include<algorithm>
using namespace std;
#define INF (1<<29)


struct Log{
	int t,n,m,s;
}lg[1000];
int numL;
int n,m;
int r,q;

int solve(int s,int e,int m){
	int res=0;
	int a=s,c=0;
	for(int i=0;i<r;i++){
		if(lg[i].m!=m)continue;
		if(lg[i].t<s){
			if(lg[i].s==1)c++;
			else c--;
			continue;
		}
		if(lg[i].t>=e){
			if(c)res += e-a;
			break;
		}
		if(lg[i].s==1){
			if(0==c++)a=lg[i].t;
		}else{
			if(0==--c){
				res += lg[i].t-a;
			}
		}
	}
	return res;
}
int main(){
	while(cin>>n>>m,n||m){
		cin>>r;
		for(int i=0;i<r;i++){
			Log &a=lg[i];
			cin>>a.t>>a.n>>a.m>>a.s;
		}
		cin>>q;
		while(q--){
			int s,e,m;
			cin>>s>>e>>m;
			cout<<solve(s,e,m)<<endl;
		}
	}
	return 0;
}