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 <algorithm>
#include <vector>
#include <tuple>

int main()
{
	while(true){
		int N, M;

		std::cin >> N >> M;
		if ( N == 0 && M == 0 ) break;

		int r;
		std::cin >> r;

		std::vector<std::tuple<int, int, int>> data(r);
		for ( int i = 0; i < r; ++i ) {
			auto &v = data[i];

			int n;
			std::cin >> std::get<0>(data[i]);
			std::cin >> n;
			std::cin >> std::get<1>(data[i]);
			std::cin >> std::get<2>(data[i]);
		}

		std::sort(data.begin(), data.end());
		int q;
		std::cin >> q;
		for ( int i = 0; i < q; ++i ) {
			int s, e, m;
			std::cin >> s >> e >> m;

			int be = s;
			int sum = 0;
			int pc = 0;
			for ( int j = 0; j < r; ++j ) {
				if ( std::get<1>(data[j]) == m ) {
					if ( std::get<2>(data[j]) == 1 ) {
						pc++;
					}else {
						pc--;
					}

					if ( be < std::get<0>(data[j]) && std::get<2>(data[j]) == 1 ) {
						if ( pc == 1 )
							be = std::get<0>(data[j]);
					}
					if ( std::get<2>(data[j]) == 0 ) {
						if ( e > std::get<0>(data[j]) ) {
							if ( pc == 0 )
								sum += std::get<0>(data[j]) - be;
						} else {
							sum += e - be;
							break;
						}
					}
				}
			}
			std::cout << sum << std::endl;
		}
	}
	
	return 0;
}

C++: #include <iostream>
#include <cstring>

using namespace std;


int students[10001][800] = {};
int numlogin[10001] = {};
int sum[10001][800]={};
int main(){

  while(1){
    int N,M,r;
    cin >> N >> M;
    if(!N and !M) break;

    cin >> r;
    // 4byte * 10^7

    memset(students,0,sizeof(students));
    memset(numlogin,0,sizeof(numlogin));

    // ?¨????
    for(int i=0; i<r; i++){ // 1000
      int t,n,m,s;
      cin >> t >> n >> m >> s;
      t -= 560;
      if(s == 0) { // ?????°??¢??????
	numlogin[m]--;
	if(numlogin[m] == 0){
	  for(int i=t-1; students[m][i] != 1 and t>=0; i--){ // 1000
	    students[m][i] = 1;
	  }
	}
      }
      else{ // ?????°??????
	numlogin[m]++;
	if(numlogin[m] == 1)
	  students[m][t] = 1;
      }
    }

    // ?´???????

    for(int i=1; i<=M; i++){ // 100000
      for(int j=1; j<1500; j++){ // 1000
	sum[i][j] = sum[i][j-1] + students[i][j]; 
	//	students[i][j] += students[i][j-1];
      }
    }

    // ??????
    int  q;
    cin >> q;
    for(int i=0; i<q; i++){
      int ts,te,id;
      cin >> ts >> te >> id;
      ts -= 560;
      te -= 560;
      cout << sum[id][te-1] - sum[id][ts] + students[id][ts] << endl;
      //      cout << students[id][te] - students[id][ts] << endl;
      //cout << students[id][te] - students[id][ts] << endl;
    }
  }
}

C++: #include <iostream>
#include <math.h>
#include <algorithm>
#include <string>

#define REP(i,n) for(int i=0; i<n; i++)
#define debug(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl;
 
#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define SIZE 722	// 1260-540
#define MAXM 10000

using namespace std;
typedef long long ll;

int data[MAXM][SIZE];

int main(){
	while(1){
		int n, m, r, q, tt, nn, mm, ss, ts, te, ans;
		
		cin >> n >> m >> r;
		if (n==0 && m==0) break;
		REP(i, MAXM){
			REP(k, SIZE){
				data[i][k] = 0;
			}
		}
		
		REP(i,r){
			scanf("%d %d %d %d", &tt, &nn, &mm, &ss);
			mm--;
			if (ss==1) data[mm][tt-540] += 1;
			else data[mm][tt-540] += -1;
		}
		
		/*/
		REP(i, SIZE){
			if (data[0][i]!=0) printf("data[%d]=%d\n", i, data[0][i]);
		}
		/*/
		
		REP(i, m){
			for (int k=1; k<SIZE; k++){
				data[i][k] += data[i][k-1];
			}
		}
		
		/*/
		REP(i, SIZE){
			if (data[0][i]>0) printf("data[%d]=%d\n", i, data[0][i]);
		}
		/*/
		
		cin >> q;
		
		REP(i,q){
			ans = 0;
			scanf("%d %d %d", &ts, &te, &mm);
			mm--;
			for (int i=ts; i<te; i++){
				if (data[mm][i-540]>0) ans++;
			}
			cout << ans << endl;
		}
		
	}
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int N,M;
  while(true){
      cin>>N>>M;
      if(N==0) break;
      int r;cin>>r;
      VVI v(M,vector<int>(1000,0));
      for(int i=0;i<r;i++){
          int t,n,m,s;cin>>t>>n>>m>>s;
          t-=540;m--;
          if(s) v[m][t]++;
          else v[m][t]--;
      }
      for(int i=0;i<M;i++){
          for(int j=1;j<=720;j++){
              v[i][j]+=v[i][j-1];
          }
      }
      int q;cin>>q;
      for(int i=0;i<q;i++){
          int ts,te,m;cin>>ts>>te>>m;
          ts-=540;te-=540;m--;
          int res=0;
          for(int j=ts;j<te;j++)if(v[m][j])res++;
          cout<<res<<endl;
      }
  }
}

C++: #include <algorithm>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;
typedef pair<int, int> pii;
int main(){
  int N, M, inf = 1000000;
  while (cin >> N >> M, N){
    int r, t, n, m, s;
    cin >> r;
    vector< vector<pii> > V(M);
    int L[N][M];
    for (int i = 0; i < r; ++i){
      cin >> t >> n >> m >> s;
      --m;
      if(s) L[n][m] = t;
      else V[m].push_back(pii(L[n][m],t));
    }
    int q, ts, te;
    cin >> q;
    for(int i = 0; i < q; ++i){
      cin >> ts >> te >> m;
      --m;
      sort(V[m].begin(),V[m].end());
      int ans = te-ts;
      for(int j = 0; j < V[m].size(); ++j){
	if(ts >= V[m][j].first) ts = max(ts,V[m][j].second);
	else{
	  ans += ts-V[m][j].first;
	  ts = V[m][j].second;
	}
	if(ts >= te) break;
      }
      if(ts < te) ans += ts-te;
      cout << ans << endl;
    }
  }
  return 0;
}