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: import copy as c
CEIL = 2000000000
lines=[]

def exploreMin(now, goal, mode, history, ans):
    #mode=0: MinCost;mode=1: MinTime
    #print(lines)
    if now == goal:
        #print('??\????????±??????')
        return ans
    if now in history: return CEIL
    minCostOrTime = CEIL
    for destination in lines[now]:
        exploreAns = exploreMin(destination[0], goal, mode, c.deepcopy(history)+[now],
                                ans+destination[mode+1])
        #print(exploreAns)
        if minCostOrTime > exploreAns: minCostOrTime = exploreAns
    return minCostOrTime
'''
def findMin(start, goal, mode):
    minAnswer=100000
    if minAnswer > xplore(start, goal, mode, []):

    return minAnswer
'''

def main():
    input1 = input().split(' ')
    global lines
    lines=[[] for i in range(int(input1[1]))]
    for lineIndex in range(int(input1[0])):
        input2 = input().split(' ')
        lines[int(input2[0])-1].append([int(input2[1])-1, int(input2[2]), int(input2[3])])
        lines[int(input2[1])-1].append([int(input2[0])-1, int(input2[2]), int(input2[3])])
    #print(lines[0][0][1])
    setnum = int(input())
    a = '\n'
    for out in range(setnum):
        if out==setnum-1: a=''
        input3 = input().split(' ')
        #print([].append(1))
        print(exploreMin(int(input3[0])-1, int(input3[1])-1, int(input3[2]), [], 0), end = a)
    input()

if __name__ == '__main__': main()

Python: from heapq import heappush, heappop

def Dijkstra(graph, start, goal):
    que = [(0, start)]
    visited = [False] * len(graph)
    while True:
        path_len, v = heappop(que)
        visited[v] = True
        if v == goal:
            print(path_len)
            break
        for w, edge_len in graph[v].items():
            if not visited[w]:
                heappush(que, (path_len + edge_len, w))

while(True):
    dicco = {}
    dicti = {}
    n,m = map(int, input().split())
    if n == 0 and m == 0:
        break
    for i in range(m):
        dicco[i] = {}
        dicti[i] = {}
    for _ in range(n):
        a,b,c,t = map(int, input().split())
        dicco[a-1][b-1] = c
        dicco[b-1][a-1] = c
        dicti[a-1][b-1] = t
        dicti[b-1][a-1] = t
    k = int(input())
    for _ in range(k):
        p,q,r = map(int, input().split())
        if not r:
            Dijkstra(dicco, p-1, q-1)
        else:
            Dijkstra(dicti, p-1, q-1)

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

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


def dijkstra(graph, start, end, total_vertices):
    h = []
    shortest_path = [0 if i == start else sys.maxsize for i in range(total_vertices + 1)]
    heapq.heappush(h, (start, 0))

    while True:
        vertex, value = heapq.heappop(h)
        if end == vertex:
            break

        for k, v in graph.get(vertex):
            if shortest_path[k] > value + v:
                shortest_path[k] = value + v
                heapq.heappush(h, (k, shortest_path[k]))

    return shortest_path


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

        # Create two maps.
        g_money = defaultdict(list)
        g_time = defaultdict(list)

        # Set two maps.
        for _ in range(n):
            start, end, money, time = map(int, input().split())
            g_money[start].append((end, money))
            g_money[end].append((start, money))
            g_time[start].append((end, time))
            g_time[end].append((start, time))

        # 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, end, s)
            print(ans[end])


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(1, V):
        for i in range(1, V):
            for j in range(i, 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 = [[9999999] * (m+1) for _ in range(m+1)]
        dp_cost = [[9999999] * (m+1) for _ in range(m+1)]
        for i in range(m+1):
            dp_time[i][i] = 0
            dp_cost[i][i] = 0

        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:])