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 <numeric>
#include <set>
#include <map>
#include <string>
#include <stack>
#include <queue>
#include <cmath>
#include <cstdio>
#include <istream>
#include <sstream>
#include <iomanip>
using namespace std;

typedef ostringstream oss;
typedef istringstream iss;

typedef vector<bool> vi;
typedef vector< vi > vvi;

const int MIN_TIME = 540;
const int MAX_TIME = 1260;


int main(void) {
	int pcNum, stuNum;
	while (cin >> pcNum >> stuNum, pcNum) {
		vector< vvi > recs(stuNum, vvi(pcNum, vi(MAX_TIME - MIN_TIME + 1, 0)));

		int recNum, queNum;
		cin >> recNum;
		for (int ri = 0; ri < recNum; ri++) {
			int time, pc, stu, type;
			cin >> time >> pc >> stu >> type;
			pc--; stu--;
			time -= MIN_TIME;
			if (type) {
				fill(recs[stu][pc].begin() + time, recs[stu][pc].end(), 1);
			}else {
				fill(recs[stu][pc].begin() + time, recs[stu][pc].end(), 0);
			}
		}

		vvi recsSum(stuNum, vi(MAX_TIME - MIN_TIME + 1, 0));
		for (int si = 0; si < stuNum; si++) {
			for (int pi = 0; pi < pcNum; pi++) {
				for (int ti = MAX_TIME - MIN_TIME; ti >= 0; ti--) {
					recsSum[si][ti] = max(recsSum[si][ti], recs[si][pi][ti]);
				}
			}
		}

		cin >> queNum;
		for (int qi = 0; qi < queNum; qi++) {
			int start, end, stu;
			cin >> start >> end >> stu;
			stu--;
			start -= MIN_TIME; end -= MIN_TIME;

			int time = 0;
			for (int ti = start; ti < end; ti++) {
				time += recsSum[stu][ti];
			}

			cout << time << endl;
		}
	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

#define MAX 1100
#define TS 590
#define TE 1100


int main(){

  while(1){
    int N,M, r, q, time[MAX][2000] = {};
    int t, n, m, s, ts, te;
    cin>>N>>M;
    if(!N&&!M)break;
    cin>>r;
    for(int i = 1; i <= r; i++){
      cin>>t>>n>>m>>s;
      if(!s){
	time[n][t+1] -= m;
      }else {
	time[n][t] += m;
      }
    }

    for(int j = 540; j <= 1260; j++){
      for(int k = 1; k <= N; k++){//cout<<time[k][j]<<" ";cout<<endl;
	time[k][j] += time[k][j-1];
      }
    }
    /*for(int j = TS; j <= TE; j++){cout<<j<<" ";
      for(int k = 1; k <= N; k++)cout<<time[k][j]<<" ";cout<<endl;
    }*/
 
    cin>>q;
    for(int i = 1; i <= q; i++){
      int ans = 0, temp = 0, f = 0;
      cin>>ts>>te>>m;
      for(int j = ts; j <= te; j++){
	for(int k = 1; k <= N; k++){
	  if(time[k][j] == m){//cout<<k<<" "<<j<<" "<<m<<endl;
		int l = j;
	    while(time[k][l+1] && l + 1 <= te)l++;
	    ans += l-j; //cout<<ans<<" =ans  "<<l<<" "<<j<<endl;
	    if(m == time[k][j-1] && j-1 >= ts)ans++;
	    //if(l != f)f = 0;
	    j = l+1;
	   // temp = j;
	    k = 1;
	  }
	}
      }
      cout<<ans<<endl;
    }
  }

  return 0;
}

C++: #include<map>
#include<set>
#include<list>
#include<cmath>
#include<queue>
#include<stack>
#include<cstdio>
#include<string>
#include<vector>
#include<complex>
#include<cstdlib>
#include<cstring>
#include<numeric>
#include<sstream>
#include<iostream>
#include<algorithm>
#include<functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
int N;//pcの数
int M;//学生の数
int r;//利用記録の数
int mae;
int sch[10010][1270];//生徒がどれだけパソコンにログインしていたか
int main(){
	while(cin>>N>>M){
		if(N==0&&M==0)
			break;
		cin>>r;
		for(int i = 0;i <=M;i++){
			for(int j = 0;j <=1260;j++){
				sch[i][j] = 0;
			}
		}
		map<pii,int> st;//学生、PC
		st.clear();
		for(int i = 0;i < r;i++){
			int t,n,m,s;//時刻t,PCn,学生m,s
			cin>>t>>n>>m>>s;
			if(s==1){
				st[pii(m,n)] = t;
			}else if(s==0){
				int mae = st[pii(m,n)];
				st.erase(pii(m,n));
				for(int j = mae;j <=t;j++){
					sch[m][j] = 1;
				}
			}
		}
		int q;
		cin>>q;
		int sum;
		for(int i = 0;i < q;i++){
			int ts,te,m;//開始、終了、学生
			cin>>ts>>te>>m;
			sum = 0;
			for(int j = ts+1;j <=te;j++){
				if(sch[m][j]&&sch[m][j-1]){
					sum++;
					//cout <<"(sum,j) = "<<sum<<" "<<j<<endl;
				}
			}
			cout <<sum<<endl;
		}
	}
	return 0;
}