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> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include <iomanip> // setprecision
#include <complex> // complex
#include <math.h> 
#define enld '\n'
using namespace std;
using ll = long long;
using P = pair<int,int>;
constexpr ll INF = 1e18;
constexpr int inf = 1e9;
constexpr ll mod = 1000000007;
constexpr ll mod2 = 998244353;
const int dx[8] = {1, 0, -1, 0,1,1,-1,-1};
const int dy[8] = {0, 1, 0, -1,1,-1,1,-1};
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
// ---------------------------------------------------------------------------


int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  while(1){
    int N,M;
    cin >> N >> M;
    if(N == 0 && M == 0) break;
    vector<vector<P>> G(M);
    int r;
    cin >> r;
    vector<int> t(r),n(r),m(r),s(r);
    for(int i=0; i<r; i++){
      cin >> t[i] >> n[i] >> m[i] >> s[i];
      m[i]--;
    }
    for(int i=0; i<r; i++){
      if(s[i] == 1){
        for(int j=i+1; j<r; j++){
          if(n[i]==n[j] && m[i]==m[j] && s[j]==0){
            G[m[i]].emplace_back(P(t[i],t[j]-1));
            break;
          }
        }
      }
    }
    int Q;
    cin >> Q;
    for(int i=0; i<Q; i++){
      int ts,te,m;
      cin >> ts >> te >> m;
      m--;
      int ans = 0;
      for(int j=ts; j<te; j++){
        for(int k=0; k<G[m].size(); k++){
          if(G[m][k].first <= j && j<=G[m][k].second){
            ans++;
            break;
          }
        }
      }
      cout << ans << "\n";
    }
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<utility>
#include<queue>
#include<algorithm>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<map>
#include<complex>
#define INF 2147483647
#define llINF 9223372036854775807
#define pb push_back
#define mp make_pair 
#define F first
#define S second
#define ll long long

using namespace std;
int main(){
  int n,m;
  while(cin>>n>>m,n){
    short ans[m][725]={};
    int r;cin>>r;
    for(int i=0;i<r;i++){
      int t,nn,mm,s;cin>>t>>nn>>mm>>s;
      mm--;
      t-=539;
      if(s==1)
	ans[mm][t]=1;
      else{
	ans[mm][t]=-1;
      }
    }
    int q;cin>>q;
    for(int i=0;i<q;i++){
      int t,tt,mm;cin>>t>>tt>>mm;mm--;
      int ans2=0;
      t-=539;
      tt-=539;
	int cnt=0;
	int cnt2=0;
      for(int j=0;j<=724;j++){
	cnt+=ans[mm][j];
	//cout<<cnt<<endl;;
	if(cnt>0&&j<=tt&&t<=j){cnt2++;}
	else{
	  ans2+=cnt2-1;
	}
      }
      cout<<ans2<<endl;
    }
  }
  return 0;
}

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

int main(void){
	int N, M;
	int t[1000], n[1000], m[1000], s[1000];
	while(cin >> N >> M, N | M){
		int r, q;
		cin >> r;
		for(int i=0; i < r; i++){
			cin >> t[i] >> n[i] >> m[i] >> s[i];
		}

		cin >> q;
		for(int i=0; i < q; i++){
			int st, et, p;
			cin >> st >> et >> p;
			int ans = 0, B;
			int A = 0;
			for(int j=0; j < r; j++){
				if(m[j] == p){
					if(s[j] == 1){
						A++;
            if(A == 1)
              B = t[j];
					}else{
						A--;
            if(A==0 && st<=t[j] && B<=et){
              ans+=(min(et, t[j]) - max(st, B));
            }
					}
				}
			}
      cout << ans << endl;
			
		}
	}
  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;

int rec[2000][1010];

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