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()
{
    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][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;
            }
            cout<<ret<<endl;
            
        }
    }
    
    return 0;
}

C++: #include<iostream>
#include<vector>
#define MAX_T 1300
using namespace std;
int main(){
  int n,m,r,q,a,b,c,d,ts,te,stu,cnt;
  cin >> n >> m;
  while(n!=0){
    vector<int> imos[10000];
    for(int i=0;i<m;i++){
      for(int j=0;j<MAX_T;j++){
        imos[i].push_back(0);
      }
    }
    cin >> r;
    for(int i=0;i<r;i++){
      cin >> a >> b >> c >> d;
      c--;
      if(d==1){
        imos[c][a]++;
      }else{
        imos[c][a]--;
      }
    }
    for(int i=0;i<m;i++){
      for(int j=1;j<MAX_T;j++){
        imos[i][j]+=imos[i][j-1];
      }
    }
//    for(int i=0;i<MAX_T;i++)cout << imos[0][i]<<"\n";
    cin >> q;
    for(int i=0;i<q;i++){
      cin >> ts >> te >> stu;
      stu--;
      cnt=0;
      for(int j=ts;j<te;j++){
        if(imos[stu][j]>0)cnt++;
      }
      cout << cnt << endl;
    }
    cin >> n >> m;
  }
}

C++: #include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<string.h>
#include<math.h>
#include<cstring>
using namespace std;

int main(){
	while(1){
		int sum,N,M,r,i,j,k,q,ts,te,start,m,rec[1001][4],in=0;
		cin>>N>>M;
		if(N==0&&M==0)break;
		cin>>r;
		for(i=0;i<r;i++){
			cin>>rec[i][0]>>rec[i][1]>>rec[i][2]>>rec[i][3];
		}
		rec[r][0]=1261;
		cin>>q;
		for(i=0;i<q;i++){
			sum=0;
			cin>>ts>>te>>m;
			if(ts<rec[0][0])ts=rec[0][0];
			if(te>rec[r-1][0])te=rec[r-1][0];
			for(j=0;rec[j][0]<ts;j++){
				if(rec[j][2]!=m)continue;
				if(rec[j][3]==1){
					in++;
				}else if(rec[j][3]==0){
					in--;
				}
			}
			if(in>0){
				start=ts;
			}else{
				start=te;
			}
			for(;rec[j][0]<te;j++){
				if(rec[j][2]!=m)continue;
				if(rec[j][3]==1&&in!=0){
					in++;
				}else if(rec[j][3]==1&&in==0){
					start=rec[j][0];
					in++;
				}else if(rec[j][3]==0&&in==1){
					in--;
					sum+=rec[j][0]-start;
					start=te;
				}else{
					in--;
				}
			}
			sum+=(te-start);
			cout<<sum<<endl;
		}
	}
    return 0;
}