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<cstdio>
#include<stack>
#include<vector>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
typedef pair<int,int> P;
stack<P> stu[10003];
vector<P> vec[10003];
int N,M,r;
int t[1003],n[1003],m[1003],s[1003];
int q;
int qs[55],qe[55],qm[55];
int main(){
  while(1){
    memset(t,0,sizeof(t));
    memset(n,0,sizeof(n));
    memset(m,0,sizeof(m));
    memset(s,0,sizeof(s));
    memset(qs,0,sizeof(qs));
    memset(qe,0,sizeof(qe));
    memset(qm,0,sizeof(qm));
    for(int i=0;i<10003;i++)vec[i].resize(0);
    for(int i=0;i<10003;i++){
      while(1){
        if(!stu[i].empty()) stu[i].pop();
        else break;
      }}

    scanf("%d%d",&N,&M);
    if(N==0 && M==0) break;
    scanf("%d",&r);
    for(int i=0;i<r;i++){
      scanf("%d%d%d%d",&t[i],&n[i],&m[i],&s[i]);
      if(s[i]==1) stu[m[i]].push(P(t[i],n[i]));
      if(s[i]==0) {
        P p=stu[m[i]].top();
        stu[m[i]].pop();
        if(stu[m[i]].empty()) vec[m[i]].push_back(P(p.first,t[i]));
      }
    }
    scanf("%d",&q);
    int i;
    for(i=0;i<q;i++) {
      scanf("%d%d%d",&qs[i],&qe[i],&qm[i]);

      int res=0;

      bool flg3=false;
      for(int j=0;j<vec[qm[i]].size();j++){
        if(vec[qm[i]][j].first <=qs[i] && vec[qm[i]][j].second >=qs[i] && vec[qm[i]][j].first <=qe[i] && vec[qm[i]][j].second >=qe[i]){
          flg3=true;
          res+=qe[i]-qs[i];
          printf("%d\n",res);
          break;
        }}
      if(flg3==true) continue;
      int j;
      bool flg1=true;
      for(j=0;j<vec[qm[i]].size();j++){
        if(vec[qm[i]][j].first <=qs[i] && vec[qm[i]][j].second >=qs[i]){
          res+=vec[qm[i]][j].second-qs[i];
          flg1=false;
          break;
        }}
      int l;
      bool flg2=true;
      for(l=0;l<vec[qm[i]].size();l++){
        if(vec[qm[i]][l].first <=qe[i] && vec[qm[i]][l].second >=qe[i]){
          res+=qe[i]-vec[qm[i]][l].first;
          flg2=false;
          break;
        }}

      if(flg3==false && flg1==false && flg2==false){
        for(int ru=j+1;ru<l;ru++) res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }
      if(flg3==false && flg1==true && flg2==false){
        for(int ru=0;ru<l;ru++)  res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }
      if(flg3==false && flg1==true && flg2==true){
        for(int ru=0;ru<vec[qm[i]].size();ru++) res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }
      if(flg3==false && flg1==false && flg2==true){
        for(int ru=j+1;ru<vec[qm[i]].size();ru++)  res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }



      printf("%d\n",res);

    }

  }
  return 0;
}

C++: 
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1148&lang=jp

#include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<numeric>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define dump(a) (cerr << #a << "=" << (a) << endl)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;

using namespace std;

int main()
{
	int N,M;

	while(cin >> N >> M && N)
	{
		vector<int> PC(N+1);
		int record[M+1][1261];
		fill_n((int *)record, sizeof(record) / sizeof(int), 0);

		int R;
		cin >> R;
		rep(nth,R)
		{
			int t,n,m,s;
			cin >> t >> n >> m >> s;
			if(s == 1){
				PC[n] = t;
			}else{
				REP(i,PC[n],t){
					record[m][i] = 1;
				}
				PC[n] = 0;
			}
		}

		int Q;
		cin >> Q;
		rep(nth,Q)
		{
			int ts, te, m;
			cin >> ts >> te >> m;
			int time=0;
			REP(i,ts,te){
				if(record[m][i]){ time+=1; }
			}
			cout << time << endl;
		}
	}

	return 0;
}

C++: #include<iostream>
 
using namespace std;
 
#define MMAX 10000
#define tMAX (60*24)

int main(void){
 
    int N, M;
    int r;
    int t, n, m1, s;
    int q;
    int ts, te, m2;
    int num,cnt;
    int data[MMAX+1][tMAX+1];
 
    while (cin >> N >> M){
        if (N == 0 && M == 0) break;
        for (int i = 0; i <= MMAX; i++){
            for (int j = 0; j <= tMAX; j++){
                data[i][j] = 0;
            }
        }
        cin >> r;
        for (int i = 0; i < r; i++){
            cin >> t >> n >> m1 >> s;
            if (s == 0) data[m1][t]--;
            else data[m1][t]++;
        }
        for (int i = 1; i <= M; i++){
            num = 0;
            for (int j = 0; j <= tMAX; j++){
                num += data[i][j];
                data[i][j] = num;
            }
        }
		cin>>q;
        for (int i = 0; i < q; i++){
            cin >> ts >> te >> m2;
            cnt = 0;
            for (int j = ts; j < te; j++){
                if (data[m2][j] >= 1) cnt++;
            }
            cout << cnt << endl;
			return 0;
        }
    }
    return 0;
}