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<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{
	  if(cnt2>0)
	  ans2+=cnt2-1;
	  cnt2=0;
	}
      }
      cout<<ans2<<endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

class hist{
public:
	int s,e;
	hist(int s,int e):s(s),e(e){};
};

bool operator < (hist a,hist b){
	if(a.s!=b.s) return a.s<b.s;
	return a.e<b.e;
}

int main()
{
	int N,M;
	while(cin>>N>>M && N!=0){
		vector<int> PC(N+1,-1);
		vector<vector<hist> > Stu(M+1);
		int r;
		cin>>r;
		for(int i=0;i<r;i++){
			int t,n,m,s;
			cin>>t>>n>>m>>s;
			if(s==0)
				Stu[m].push_back(hist(PC[n],t));
			else{
				PC[n]=t;
			}
		}
		int q;
		cin>>q;
		for(int i=0;i<q;i++){
			int s,e,m;
			cin>>s>>e>>m;
			sort(Stu[m].begin(),Stu[m].end());
			int ans=0;
			int time=s;
			for(int k=0;k<Stu[m].size();k++){
				if(Stu[m][k].e<time) continue;
				if(min(Stu[m][k].e,e)-max(time,Stu[m][k].s)<0) continue;
				ans+=min(Stu[m][k].e,e)-max(time,Stu[m][k].s);
				time=min(Stu[m][k].e,e);
			}
			cout<<ans<<endl;
		}
	}
}

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

using namespace std;

const int MaxN = 1001;
const int MaxM = 10001;

int N, M;

int main() {
  int count[MaxM];

  while(cin>>N>>M && !(N==0 && M==0)) {
    vector < vector< pair<int,int> > > logg(MaxM);
    int r;
    cin>>r;
    int t,n,m,s;
    for(int i=0; i<MaxM; i++) { // 初期化
      count[i] = 0;
    }
    for(int i=0; i<r; i++) {
      cin>>t>>n>>m>>s;
      if(s == 1) { // login
	count[m]++;
	if(count[m] == 1) {
	  logg[m].push_back(make_pair(t,t));
	}
      }
      else { // logout
	count[m]--;
	if(count[m] == 0) {
	  logg[m].back().second = t;
	}
      }
    }
    int q;
    cin>>q;
    for(int i=0; i<q; i++) {
      int ts, te, m, ans = 0;
      cin>>ts>>te>>m;
      for(int j=0; j<logg[m].size(); j++) {
	/*if(logg[m][j].first < te) {
	  ans += min(te, logg[m][j].second)-max(ts, logg[m][j].first);
	}*/
	ans += max(0, min(te,logg[m][j].second)-max(ts,logg[m][j].first));
      }
      cout<<ans<<endl;
    }
  }
}

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

using namespace std;

int main()
{
    int N, M;
    while (cin >> N >> M, N|M) {
        int use[10001];
        int start[10001];
        fill_n((int *)use, 10001, 0);
        vector<pair<int, int>> vpii[10001];

        // data
        int r;
        cin >> r;
        for (int i = 0; i < r; i++) {
            int t, n, m, s;
            cin >> t >> n >> m >> s;
            if (s == 1) { // login
                if (use[m] == 0) {
                    start[m] = t;
                }
                use[m]++;
            } else { // logout
                use[m]--;
                if (use[m] == 0) {
                    vpii[m].push_back({start[m], t});
                }
            }
        }

        // query
        int q;
        cin >> q;
        for (int i = 0; i < q; i++) {
            int ts, te, m;
            cin >> ts >> te >> m;
            int total = 0;
            for (auto pii: vpii[m]) {
                if (te <= pii.first || ts >= pii.second)
                    continue;
                int left, right;
                left = pii.first > ts ? pii.first : ts;
                right = pii.second < te ? pii.second : te;
                total += right - left;
            }
            cout << total << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
 
using namespace std;
 
#define MMAX 1000000
#define tMAX (60*24)*10
int main(){
 
    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 (1){
        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;
}