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]
					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: """ Created by Jieyi on 7/28/16. """
import sys


def dijkstra(path_map, start=0):
    arr_shortest_path = path_map[start]
    stack = []

    # Until all vertices put into stack.
    while 1:
        if len(stack) is len(arr_shortest_path):
            break

        # Pick the smallest value from the arr_shortest_path is not including vertices in the stack.
        tmp_arr = arr_shortest_path[:]
        for i in range(len(stack)):
            tmp_arr[stack[i]] = sys.maxsize
        mini_vertex = arr_shortest_path.index(min(tmp_arr))
        stack.append(mini_vertex)

        # Calculate the smallest value's vertex with all vertices which it could go.
        for i in range(len(arr_shortest_path)):
            if arr_shortest_path[i] > arr_shortest_path[mini_vertex] + path_map[mini_vertex][i]:
                arr_shortest_path[i] = arr_shortest_path[mini_vertex] + path_map[mini_vertex][i]

    return arr_shortest_path


def algorithm():
    while True:
        n, s = map(int, input().split())
        if n == 0 and s == 0:
            break

        # Create two maps.
        g_money = [[sys.maxsize for _ in range(s)] for _ in range(s)]
        for c in range(s):
            g_money[c][c] = 0
        g_time = g_money[:]

        # Set two maps.
        for _ in range(n):
            x, y, m, t = map(int, input().split())
            x, y = x - 1, y - 1
            g_money[x][y], g_time[x][y] = m, t

        # Calculate the shortest path.
        for n in range(int(input())):
            start, end, category = list(map(int, input().split()))
            m = {0: g_money, 1: g_time}.get(category)
            ans = dijkstra(m, start - 1)
            print(ans[end - 1])


def main():
    algorithm()


if __name__ == '__main__':
    main()

Python: """ Created by Jieyi on 7/28/16. """
import copy
import io
import sys
from collections import defaultdict
import heapq

if len(sys.argv) > 1:
    filename = sys.argv[1]
    inp = ''.join(open(filename, "r").readlines())
    sys.stdin = io.StringIO(inp)


def dijkstra(p, q, E):
    h = []
    d = defaultdict(lambda: 100000000)
    heapq.heappush(h, (0, p))

    while h:
        c, i = heapq.heappop(h)
        if i == q:
            return c
        for j in E[i]:
            nc = c + E[i][j]
            if d[j] > nc:
                d[j] = nc
                heapq.heappush(h, (nc, j))


def algorithm():
    while True:
        n, s = map(int, input().split())
        if n == 0 and s == 0:
            break

        # Create two maps.
        # g_money = [[sys.maxsize for _ in range(s)] for _ in range(s)]
        # g_time = copy.deepcopy(g_money)
        g_money = defaultdict(defaultdict)
        g_time = defaultdict(defaultdict)

        # Set two maps.
        for _ in range(n):
            x, y, m, t = map(int, input().split())
            g_money[x - 1][y - 1] = m
            g_time[x - 1][y - 1] = t

        # Calculate the shortest path.
        for n in range(int(input())):
            start, end, category = list(map(int, input().split()))
            m = {0: g_money, 1: g_time}.get(category)

            print(dijkstra(start - 1, end - 1, m))


def main():
    algorithm()


if __name__ == '__main__':
    main()

Python: # -*- coding: utf-8 -*-
"""
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=0200

"""
import sys
from sys import stdin
input = stdin.readline


def warshallFloyd(V, dp):
    for k in range(V):
        for i in range(V):
            for j in range(V):
                if dp[i][k] + dp[k][j] < dp[i][j]:
                    dp[i][j] = dp[i][k] + dp[k][j]


def main(args):
    while True:
        n, m = map(int, input().split())
        if n == 0 and m == 0:
            break
        dp_time = [[float('inf')] * (m+1) for _ in range(m+1)]
        dp_cost = [[float('inf')] * (m+1) for _ in range(m+1)]
        for _ in range(n):
            a, b, cost, time = map(int, input().split())
            dp_time[a][b] = time
            dp_time[b][a] = time
            dp_cost[a][b] = cost
            dp_cost[b][a] = cost

        warshallFloyd(m+1, dp_time)
        warshallFloyd(m+1, dp_cost)

        k = int(input())
        for _ in range(k):
            p, q, r = map(int, input().split())
            if r == 0:
                print(dp_cost[p][q])
            else:
                print(dp_time[p][q])



if __name__ == '__main__':
    main(sys.argv[1:])

Python: import heapq

def dijkstra(s,g,m):
    global pq
    global d
    color=[0]*n
    d=[float('inf')]*n
    d[s]=0
    heapq.heappush(pq,[0,s])
    while len(pq)!=0:
        t,u=heapq.heappop(pq)
        color[u]=2
        if d[u]<t:
            continue
        for v in g[u]:
            if color[v]!= 2:
                if d[u]+m[u][v]<d[v]:
                    d[v]=d[u]+m[u][v]
                    color[v]=1
                    heapq.heappush(pq,[d[v],v])

while 1:
    pq=[]
    n,m=map(int,raw_input().split())
    g=[[] for _ in xrange(m)]
    cost=[[0]*m for _ in xrange(m)]
    time=[[0]*m for _ in xrange(m)]
    if n==m==0:
        break
    for i in xrange(n):
        a,b,c,t=map(int,raw_input().split())
        g[a-1].append(b-1)
        g[b-1].append(a-1)
        cost[a-1][b-1]=c
        cost[b-1][a-1]=c
        time[a-1][b-1]=t
        time[b-1][a-1]=t
    k=input()
    for i in xrange(k):
        p,q,r=map(int,raw_input().split())
        if r==0:
            dijkstra(p-1,g,cost)
            print(d[q-1])
        else:
            dijkstra(p-1,g,time)
            print(d[q-1])