Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var scanner = bufio.NewScanner(os.Stdin)

const INF = 0x7FFFFFFF

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		n, _ := strconv.Atoi(buf[0])
		m, _ := strconv.Atoi(buf[1])
		if n == 0 && m == 0 {
			break
		}
		c_matrix := make([][]int, m)
		for i := range c_matrix {
			c_matrix[i] = make([]int, m)
		}
		t_matrix := make([][]int, m)
		for i := range t_matrix {
			t_matrix[i] = make([]int, m)
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			a, _ := strconv.Atoi(buf_[0])
			b, _ := strconv.Atoi(buf_[1])
			c, _ := strconv.Atoi(buf_[2])
			t, _ := strconv.Atoi(buf_[3])
			c_matrix[a-1][b-1] = c
			t_matrix[a-1][b-1] = t
		}
		c_dist := make([][]int, m)
		c_prev := make([][]int, m)
		t_dist := make([][]int, m)
		t_prev := make([][]int, m)
		for i := 0; i < m; i++ {
			c_dist[i] = make([]int, m)
			c_prev[i] = make([]int, m)
			t_dist[i] = make([]int, m)
			t_prev[i] = make([]int, m)
		}
		for i := 0; i < m; i++ {
			for j := 0; j < m; j++ {
				if c_matrix[i][j] == 0 {
					c_dist[i][j] = INF
					c_prev[i][j] = -1
				} else {
					c_dist[i][j] = c_matrix[i][j]
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0 {
					t_dist[i][j] = INF
					t_prev[i][j] = -1
				} else {
					t_dist[i][j] = t_matrix[i][j]
					t_prev[i][j] = i
				}
			}
			c_dist[i][i] = 0
			t_dist[i][i] = 0
		}
		for k := 0; k < m; k++ {
			for i := 0; i < m; i++ {
				for j := 0; j < m; j++ {
					c_newlen := c_dist[i][k] + c_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[k][j]
					}
				}
			}
		}
		for k := 0; k < m; k++ {
			for i := 0; i < m; i++ {
				for j := 0; j < m; j++ {
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if t_newlen < t_dist[i][j] {
						t_dist[i][j] = t_newlen
						t_prev[i][j] = t_prev[k][j]
					}

				}
			}
		}
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < k; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			p, _ := strconv.Atoi(buf_[0])
			q, _ := strconv.Atoi(buf_[1])
			r, _ := strconv.Atoi(buf_[2])
			switch r {
			case 0:
				fmt.Println(c_dist[p-1][q-1])
			case 1:
				fmt.Println(t_dist[p-1][q-1])
			}
		}
	}
}

Python: cost_ans = []
time_ans = []

def set_ans(cost , time):
    cost_ans.append(cost)
    time_ans.append(time)

def reset_ans():
    global cost_ans
    global time_ans
    cost_ans = []
    time_ans = []

class Sta(object):
    """station"""
    def __init__(self, station_name):
        super(Sta, self).__init__()
        self.station_name = station_name
        self.route = []

    def add_route(self, route):
        self.route.append(route)



class Route(object):
    """route"""
    def __init__(self, cost, time, next_station):
        super(Route, self).__init__()
        self.time = time
        self.cost = cost
        self.next_station = next_station

def search_route(now_station, gool_station, cost, time):
    """search route"""

    if now_station.station_name == gool_station.station_name:
        set_ans(cost, time)
        return

    elif len(now_station.route) == 0:
        return

    for r in now_station.route:
        search_route(
                r.next_station,
                gool_station,
                cost + r.cost,
                time + r.time)


def main():

    while True:
        reset_ans()
        n,m = map(int, raw_input().split())
        if n == 0 and m == 0:
            return

        stations = [Sta(x) for x in xrange(1,m+1) ]

        for i in xrange(n):
            a, b, cost, time = map(int, raw_input().split())
            tmp = Route(cost, time, stations[b-1])
            stations[a-1].add_route(tmp)

        k = input()
        for i in xrange(k):
            p, q, r = map(int, raw_input().split())
            search_route(stations[p-1], stations[q-1], 0, 0)
            if r == 0:
                print(min(cost_ans))
            else:
                print(min(time_ans))



if __name__ == '__main__':
    main()

Python: # coding: utf-8
class Route:
    def __init__(self, station_number, price, jikan):
        self.station_number = station_number
        self.price = price
        self.jikan = jikan

class Station:
    def __init__(self):
        self.routes = []
    def addRoute(self,route):
        self.routes.append(route)

class Path:
    def __init__(self, now_station, next_station, price, jikan):
        self.now_station = now_station
        self.next_station = next_station
        self.price = price
        self.jikan = jikan

def search_path(stations, come_from, go_to, search_type):
    result = [9999999999]
    q = []
    for distination in stations[come_from].routes:
        new_path = Path(come_from, distination.station_number, distination.price, distination.jikan)
        q.append(new_path)
    while len(q) > 0:
        path = q.pop(0)
        if path.next_station == go_to:
            r = path.price if search_type == 0 else path.jikan
            result.append(r)
        for distination in stations[path.next_station].routes:
            update_price = path.price + distination.price
            update_jikan = path.jikan + distination.jikan
            next_path = Path(path.next_station, distination.station_number, update_price, update_jikan)
            q.append(next_path)
    print(sorted(result)[0])

route_count, station_count = map(int, input().split(" "))
stations = [Station() for i in range(station_count)]
for read_line in range(route_count):
    come_from, go_to, price, jikan = map(int, input().split(" "))
    route = Route(go_to - 1, price, jikan)
    stations[come_from - 1].addRoute(route)
search_count = int(input())
for read_line in range(search_count):
    come_from, go_to, search_type = map(int, input().split())
    search_path(stations, come_from - 1, go_to - 1, search_type)

Python: # coding: utf-8
class Route:
    def __init__(self, station_number, price, time):
        self.station_number = station_number
        self.price = price
        self.time = time

class Station:
    def __init__(self):
        self.routes = []
    def addRoute(self,route):
        self.routes.append(route)

class Path:
    def __init__(self, now_station, next_station, price, time):
        self.now_station = now_station
        self.next_station = next_station
        self.price = price
        self.time = time

def search_path(stations, come_from, go_to, search_type):
    pass
#   result = []
#   q = []
#   for distination in stations[come_from].routes:
#       new_path = Path(come_from, distination.station_number, distination.price, distination.time)
#       q.append(new_path)
#   while len(q) > 0:
#       path = q.pop(0)
#       if path.next_station == go_to:
#           r = path.price if search_type == 0 else path.time
#           result.append(r)
#       for distination in stations[path.next_station].routes:
#           update_price = path.price + distination.price
#           update_time = path.time + distination.time
#           next_path = Path(path.next_station, distination.station_number, update_price, update_time)
#           q.append(next_path)
#   print(sorted(result)[0])

route_count, station_count = map(int, input().split(" "))
stations = [Station() for i in range(station_count)]
for read_line in range(route_count):
    come_from, go_to, price, time = map(int, input().split(" "))
    route = Route(go_to - 1, price, time)
    stations[come_from - 1].addRoute(route)
search_count = int(input())
for read_line in range(search_count):
    come_from, go_to, search_type = map(int, input().split())
    search_path(stations, come_from - 1, go_to - 1, search_type)