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;

      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(flg1==false && flg2==false){
        for(int ru=j+1;ru<l;ru++) res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }
      if(flg1==true && flg2==false){
        for(int ru=0;ru<l;ru++)  res+=vec[qm[i]][ru].second-vec[qm[i]][ru].first;
      }
      if(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(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++: #include<iostream>
#include<algorithm>
#include<string>
#include<vector>
using namespace std;
#define REP(i, a, n) for(int i=a; i<n; i++)

int record[10001][721];
int main()
{
	int N, M;
	while (cin >> N >> M, N || M) {
		int r, q;
		REP(i, 0, M) {
			REP(j, 0, 721) {
				record[i][j] = 0;
			}
		}

		cin >> r;
		REP(i, 0, r) {
			int t, n, m, s;
			cin >> t >> n >> m >> s;
			t -= 540;
			n--;
			m--;
			if (s == 1) record[m][t]++;
			else record[m][t]--;
		}

		REP(i, 0, M) {
			REP(j, 0, 720) {
				record[i][j + 1] += record[i][j];
			}
		}

		cin >> q;
		REP(i, 0, q) {
			int start, end, m, sum = 0;;
			cin >> start >> end >> m;
			start -= 540;
			end -= 540;
			m--;

			REP(j, start, end) {
				if (record[m][j] != 0) sum++;
			}

			cout << sum << endl;
		}

	}

	return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
const int MAXTIME = 1260;
void fill(vector<bool> &a,int s,int l){
  for(int i = s;i < l;i++){
    a[i] = true;
  }
  return;
}
int solve(vector<bool> &a,int s,int l){
  int ans = 0;
  for(int i = s;i < l;i++){
    if(a[i]){
      ans++;
    }
    /*    if(a[i] == 1 && a[i+1] == 0){
      ans--;
      }*/
  }
  return ans;
}
int main(){
  while(1){
    int N,M;
    cin >> N >> M;
    if(N == 0 && M == 0)break;
    vector<vector<bool> > students(M,vector<bool>(MAXTIME+2,false));
    //int students[10000][1260] = {0};
    vector<vector<int> > keep(M,vector<int>(N+1,0));


    int r;
    cin >> r;
    for(int i = 0;i < r;i++){
      int t,n,m,s;
      cin >> t >> n >> m >> s;
      if(s == 0){
	fill(students[m-1],keep[m-1][n-1],t);
      }else if(s == 1){
	keep[m-1][n-1] = t;
      }
    }
    int q;
    cin >> q;
    for(int i = 0;i < q;i++){
      int ts,te,m;
      cin >> ts >> te >> m;
      cout << solve(students[m-1],ts,te) << endl;
    }
  }
  
  return 0;
}