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 <bits/stdc++.h>
#define r(i,a,n) for(int i=a;i<n;i++)
using namespace std;
int main(){
	int n,p,a[10000][1261-539],ch[10000][1261-539];
	while(cin>>n>>p,n){
		int q,b,c,d,e;
		r(i,0,p)r(j,0,1261-539)ch[i][j]=a[i][j]=0;
		cin>>q;
		r(i,0,q){
			cin>>b>>c>>d>>e;
			b-=539;
			if(e==1){a[d-1][b]++;ch[d-1][b]=c;}
			else{
				for(int j=b-1;j>=0;j--){
					if(ch[d-1][j]==c)break;
					a[d-1][j]++;
				}
			}
		}
		cin>>q;
		while(q--){
			int s=0;
			cin>>b>>c>>d;
			b-=539;
			c-=539;
			r(i,b,c)if(a[d-1][i])s++;
			cout<<s<<endl;
		}
	}
}

C++: #include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
using namespace std;
#define INF 100000000

typedef long long ll;
typedef pair<int, int> P;

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};

int main(void) {
    int N, M, r;
    while (1) {
        cin >> N >> M;
        if (N == 0 && M == 0) break;
        cin >> r;
        vector<P> students[M+1];
        for (int i = 0; i < r; i++) {
            int t, n, m, s;
            cin >> t >> n >> m >> s;
            students[m].push_back(make_pair(t, s));
        }
        for (int i = 1; i <= M; i++) {
            sort(students[i].begin(), students[i].end());
        }
        int q;
        cin >> q;
        for (int i = 0; i < q; i++) {
            int s, e, m;
            cin >> s >> e >> m;
            int time = s, cnt = 0, ans = 0;
            for (int j = 0; j < students[m].size(); j++) {
                P p = students[m][j];
                if (cnt > 0) {
                    ans += min(p.first, e) - time;
                }
                time = max(s, min(p.first, e));
                cnt += p.second ? 1 : -1;
            }
            cout << ans << endl;
        }
    }
    return 0;
}

C++: #include <iostream>
#include <map>
#include <algorithm>
#include <vector>
#include <stack>
#include <math.h>

using namespace std;

#define T 800

int main(int argc, char const *argv[])
{
	int N,M;
	int r;
	int t,n,m,s;
	int q;
	int ts,te;
	int ans;

	while(1){
		cin>>N>>M;
		if(N+M==0) break;

		map<int,vector<int> > lio;

		for(int i1=0;i1<M;i1++){
			vector<int> v(T);
			fill(v.begin(), v.end(),0);
			lio[i1]=v;
		}

		cin>>r;
		for(int i1=0;i1<r;i1++){
			cin>>t>>n>>m>>s;
			vector<int> v=lio[m-1];
			if(s==1) v[t-540]+=1;
			else if(s==0) v[t-540]+=-1;
			lio[m-1]=v;
			
		}

		for(int i1=0;i1<M;i1++){
			vector<int> v=lio[i1];
			for(int i2=1;i2<T;i2++){
				v[i2]=v[i2-1]+v[i2];
			}
			lio[i1]=v;
		}

		cin>>q;
		for(int i1=0;i1<q;i1++){
			cin>>ts>>te>>m;

			vector<int> v=lio[m-1];
			ans=0;
			for(int i2=ts-540;i2<te-540;i2++){
				if(v[i2]>0) ans++;
			}
			cout<<ans<<endl;
		}



	}
	return 0;
}

C++: #include <stdio.h>

#define M_MAX         10000
#define N_MAX         1000
#define r_MAX         1000
#define q_MAX         50
#define DATASET_MAX   10
#define TS_MIN        540
#define TE_MAX        1260
#define USETIME_MAX   TE_MAX-TS_MIN

struct LogInfo{
    int PCNum;
    int LogInTime;
    int LogOutTime;
};

int LogInCnt[M_MAX];
struct LogInfo LogInfoData[M_MAX][r_MAX];
int UsePCTime[DATASET_MAX];

void VarInit( void ){
    int i;
    int j;
    
    for( i=0; i<M_MAX; i++ ){
        LogInCnt[i] = 0;
        for( j=0; j<r_MAX; j++ ){
            LogInfoData[i][j].PCNum = 0;
            LogInfoData[i][j].LogInTime = 0;
            LogInfoData[i][j].LogOutTime = 0;
        }
    }
}


void RecLogInInfo( int t, int n, int m ){
    LogInfoData[m][LogInCnt[m]].PCNum = n;
    LogInfoData[m][LogInCnt[m]].LogInTime = t;
    LogInCnt[m]++;
}

void RecLogOutInfo( int t, int n, int m ){
    int i;
    
    for( i=0; i<LogInCnt[m]; i++ ){
        if( (LogInfoData[m][i].PCNum == n) && (LogInfoData[m][i].LogOutTime == 0)){
            LogInfoData[m][i].LogOutTime = t;
        }
    }
}

int CalcUsePCTime( int ts, int te, int m ){
    int i,j,t1,t2,Time;
    int Work[USETIME_MAX+1];
    Time = 0;
    
    for( i=0; i<USETIME_MAX+1; i++){
        Work[i] = 0;
    }
    
    for( i=0; i<LogInCnt[m]; i++ ){
        t1 = LogInfoData[m][i].LogInTime-TS_MIN;
        t2 = LogInfoData[m][i].LogOutTime-TS_MIN;
        for( j=t1; j<t2; j++){
            Work[j] = 1;
        }
    }
    
    for( i=ts; i<=te; i++){
        if(Work[i-TS_MIN] == 1){
        Time++;
        }
    }
    
    return Time;
}


int main( void ){
    int i,N,M,r,q,t,n,m,s,ts,te;
    int qNum;
    int UseTime;
    
    qNum = 0;
    for( i=0; i<DATASET_MAX; i++ ){
        UsePCTime[i] = 0;
    }
    while( 1 ){
        scanf( " %d %d", &N, &M );
        if( N == 0 ){
            break;
        }
        VarInit();
        scanf( " %d", &r );
        for( i=0; i<r; i++ ){
            scanf( " %d %d %d %d", &t, &n, &m, &s );
            if( s == 1 ){
                RecLogInInfo( t, n, m );
            }else{
                RecLogOutInfo( t, n, m );
            }
        }
        
        scanf( " %d", &q );
        for( i=0; i<q; i++ ){
            scanf( " %d %d %d", &ts, &te, &m );
            UseTime = CalcUsePCTime( ts, te, m );
            printf("%d\n",UseTime);
        }
    }
}