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>
using namespace std;
 
int main() {
    int n,m,r,q,t,nn,mm,s,ts,te;
    int si[10001]={};
    int ei[10001]={};
    int pcn[10001]={};
    int lts[1000]={};
    int lte[1000]={};
    int ni[1000]={};
    while(1){
        cin >> n >> m;
        if(n==0){return 0;}
        for(int i=1;i<=m;i++){
            si[i]=-1;
            pcn[i]=0;
        }
        cin >> r;
        int pi=0;
        for(int i=0;i<r;i++){
            cin >> t >> nn >> mm >> s;
            if(s){
                pcn[mm]++;
                if(pcn[mm]==1){
                    if(si[mm]==-1){
                        si[mm]=pi;
                    }else{
                        ni[ei[mm]]=pi;
                    }
                        ei[mm]=pi;
                        lts[pi]=t;
                        ni[pi]=-1;
                        pi++;
                }
            }else{
                pcn[mm]--;
                if(pcn[mm]==0){
                    lte[ei[mm]]=t;
                }
            }
        }
        cin >> q;
        for(int i=0;i<q;i++){
            cin >> ts >> te >> mm;
            int tt=0;
            for(int j=si[mm];j!=-1;j=ni[j]){
                if(lts[j]<ts && lte[j]>=ts && lte[j]< te){
                    tt=lte[j]-ts;
                }
                if(lts[j]<ts && lte[j]>=te){
                    tt=te-ts;
                    break;
                }
                if(lts[j]>=ts && lte[j]<te){
                    tt+=lte[j]-lts[j];
                }
                if(lts[j]>=ts && lts[j]<te && lte[j]>te){
                    tt+=te-lts[j];
                    break;
                }
                if(lts[j]>=te){
                    break;
                }
            }
            cout << tt << endl;
        }
    }
}

C++: #include <iostream>
#include <vector>
#include <cstring>
#include <cstdio>
#define rep(i,a,b) for(int i=(a); i<(b); i++)

using namespace std;
int N , M;

typedef struct data {
  int time , pc , user , on;
} data;

int main(){
  while(cin >> N >> M , N + M){
    data input[1000];
    
    int r; cin >> r;
    rep(i,0,r){
      int time , pc , user , on;
      cin >> input[i].time >> input[i].pc >> input[i].user >> input[i].on;
    }
    int q; cin >> q;
    rep(i,0,q){
      int ans = 0;
      int on = 0;
      int ts,te,user; cin >> ts >> te >> user;
      rep(j,0,r){
        if(input[j].user != user) continue;
        if(input[j].on) on++;
        else on--;
        if(!on){
          int k=j-1;
          while(input[k].pc != input[j].pc) k--;
          int start = max(input[k].time , ts);
          int end = min(input[j].time , te);
          if(end - start >= 0){
            ans += end - start;
          }
        }
      }
      cout << ans << endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <stack>

using namespace std;

#define INF 1010001000
#define EPS 1e-10
#define rep(i, N) for (int i = 0; i < N; i++)
#define pb push_back

typedef pair<int, int> i_i;
typedef long long int llong;
typedef pair<llong, llong> ll_ll;
typedef struct edge {int f, t;}Edge;


int main()
{
    int n, m;
    while (cin >> n >> m, n) {
        int r;
        cin >> r;
        vector<vector<int> > solve(m+1, vector<int>(1261, 0));
        rep(i, r) {
            int a, b, c, d;
            cin >> a >> b >> c >> d;
            if (d) {
                solve[c][a]++;
            } else {
                solve[c][a]--;
            }
        }
        for (int j = 1; j <= m; j++) {
            for (int i = 540; i < 1260; i++) {
                solve[j][i+1] += solve[j][i];
            }
        }
        int q;
        cin >> q;
        rep(i, q) {
            int a, b, c;
            cin >> a >> b >> c;
            int ret = 0;
            for (int j = a; j < b; j++) {
                if (solve[c][j]) {
                    ret++;
                }
            }
            cout << ret << endl;
        }
    }
    return 0;
}