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<algorithm>
#include<cctype>
#include<utility>
#include<string>
#include<cmath>
#include<cstring>
#include<queue>
#include<map>
#include<climits>

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
using namespace std;
typedef pair<int, int> P;
typedef long long int ll;
typedef pair<ll,ll> LLP;
#define INF 1000000007
#define MOD 1000000007

#define MAX_N 1005

int tm[MAX_N][MAX_N];//tm[人数][時間]

int main(){

    int n,m;
    while(cin >> n >> m,n){//PC数、学生数

        REP(i,MAX_N){
            REP(j,MAX_N){
                tm[i][j] = 0;
            }
        }
        int r,t,pc,num,s,q;
        cin >> r;
        REP(i,r){
            cin >> t >> pc >> num >> s;
            num--;//配列の添え字に合わせる
            t-=540;//配列0スタートに合わせる
            if(s == 1){
                //ログイン
                tm[num][t+1]++;
            }else{
                //ログアウト
                tm[num][t+1]--;
            }
        }

        //累積和
        REP(i,m){
            REP(j,MAX_N-1){
                tm[i][j+1] += tm[i][j];//imos累積和
            }
            REP(j,MAX_N){
                if(tm[i][j] > 1){
                    tm[i][j] = 1;
                }
            }
            REP(j,MAX_N-1){
                tm[i][j+1] += tm[i][j];//累積和
            }
        }

        cin >> q;//クエリ

        int ts,tr;
        REP(i,q){
            cin >> ts >> tr >> num;//時刻tsから時刻trまでのnumの利用時間
            num--;
            ts-=540;
            tr-=540;
            cout << tm[num][tr] - tm[num][ts] << endl;
        }
    }


    return 0;
}

C++: #include<iostream>

using namespace std;

#define MMAX 10000
#define tMAX 1260

int main(){

	int N,M;
	int r;
	int t,n,m,s;
	int q;
	int ts,te;
	int score[MMAX+1][tMAX+1];
	int cnt[MMAX+1];
	int tim[MMAX+1];
	int cou;

	while(1){

		cin>>N>>M;
		if(N==0&&M==0) break;
		cin>>r;
		for(int i=1;i<M;i++){
			cnt[i]=0;
			tim[i]=0;
			for(int j=0;j<=1260;j++){
				score[i][j]=0;
			}
		}

		for(int i=0;i<r;i++){
			cin>>t>>n>>m>>s;
			if(s==1){
				if(cnt[m]==0){
					tim[m]=t;
					cnt[m]++;
				}
			}
			else{
				if(cnt[m]==1){
					for(int i=tim[m];i<=t;i++){
						score[m][i]=1;
					}
				}
			}
		}

		cin>>q;

		for(int i=0;i<q;i++){
			cin>>ts>>te>>m;
			cou=0;
			for(int i=ts;i<te;i++){
				if(score[m][i]>=1) cou++;
			}
			cout<<cou<<endl;
		}
	}

	return 0;
}

C++: #include<iostream>
#include<utility>
#include<cstring>
using namespace std;

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

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][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;
            }
            cout<<ret<<endl;
            
        }
    }
    
    return 0;
}