Go: // Warshall–Floyd Algorithm

package main

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

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
				} else {
					c_dist[i][j] = c_matrix[i][j]
				}
				if c_matrix[i][j] == 0{
					c_prev[i][j] = -1
				} else {
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0{
					t_dist[i][j] = INF
				} else {
					t_dist[i][j] = t_matrix[i][j]
				}
				if t_matrix[i][j] == 0{
					t_prev[i][j] = -1
				} else {
					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]
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[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: while True:
    n, m = list(map(int,input().split()))
    if n == 0 and m == 0:
        break
    # ??°????????\???
    cost =  [[10000000 for i in range(m+1)] for j in range(m+1)]
    time =  [[10000000 for i in range(m+1)] for j in range(m+1)]
    for i in range(n):
        a, b, c, t = list(map(int, input().split()))
        cost[a][b] = cost[b][a] = c
        time[a][b] = time[b][a] = t

    # ???????????£???????????????
    for k in range(m+1):
        for i in range(m+1):
            for j in range(m+1):
                cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j])
                time[i][j] = min(time[i][j], time[i][k] + time[k][j])

    # ????????????
    k = int(input())
    p = []
    for i in range(k):
        p = list(map(int, input().split()))
        if p[2] == 0: print(cost[p[0]][p[1]])
        else: print(time[p[0]][p[1]])

Python: cost_ans = []
time_ans = []

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

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:
        set_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: import sys
import heapq as h

inf = sys.maxsize

# おまじない
class heapq:
    def __init__(self):
        self.q = []

    def push(self,v):
        h.heappush(self.q, v)
    
    def pop(self):
        return h.heappop(self.q)

    def is_empty(self):
        return len(self.q) == 0

# 入力:graphと始点s
# 出力:始点sから各頂点tへの距離dist
def shortestPath0(graph, s, t):
    n = len(graph)

    dist    = [inf for _ in range(n)]
    visited = [False for _ in range(n)]
    dist[s] = 0

    while True:
        idx, u  = -1, inf
        for i in range(n):
            if not visited[i] and dist[i] < u:
                idx = i
                u = dist[i]
        
        if u == inf: break
        
        visited[idx] = True

        for (next, w) in graph[idx]:
            newdist = w + dist[idx]
            if newdist < dist[next]:
                dist[next] = newdist
    return dist

def shortestPath1(graph, s, t):
    n = len(graph)

    dist    = [inf for _ in range(n)]
    visited = [False for _ in range(n)]
    
    q = heapq()
    q.push((0, s))

    while not q.is_empty():
        (cur_dist, v) = q.pop()
        if v == t:
            return cur_dist

        if visited[v] or dist[v] <= cur_dist:
            continue

        dist[v] = cur_dist
        visited[v] = True

        for next, w in graph[v]:
            if not visited[next] and dist[v] + w < dist[next]:
                q.push((dist[v] + w, next))

def main():
    while True:
        n, m = map(int, input().split())
        if n == 0 and m == 0:
            break
        # 隣接リスト
        tgraph = [[] for _ in range(m)]
        cgraph = [[] for _ in range(m)]
        
        for i in range(n):
            a, b, cost, time = map(int, input().split())
            a -= 1
            b -= 1
            cgraph[a].append((b, cost))
            cgraph[b].append((a, cost))
            tgraph[a].append((b, time))
            tgraph[b].append((a, time))
            

        k = int(input())
        for i in range(k):
            p, q, r = map(int, input().split())
            p-=1
            q-=1
            if p > q:
                p, q = q, p
            if r == 0:
                print(shortestPath1(cgraph, p, q))
            else:
                print(shortestPath1(tgraph, p, q))
main()