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: # -*- 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(1, 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 sys
from copy import deepcopy


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 = deepcopy(g_money)

        # Set two maps.
        for _ in range(n):
            x, y, money, time = map(int, input().split(' '))
            x -= 1
            y -= 1
            g_money[x][y] = money
            g_time[x][y] = 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 - 1)
            print(ans[end - 1])


def main():
    algorithm()


if __name__ == '__main__':
    main()

Python: # AOJ 0200 Traveling Alone: One-way Ticket of Youth
# Python3 2018.6.24 bal4u
# ワーシャルフロイド法

INF = 0x7fffffff

while 1:
	n, m = map(int, input().split())
	if n == 0: break
	tim = [[INF for j in range(m)] for i in range(m)]
	fee = [[INF for j in range(m)] for i in range(m)]
	for i in range(m): tim[i][i] = fee[i][i] = 0;
	for i in range(n):
		a, b, c, t = map(int, input().split())
		a -= 1
		b -= 1
		if fee[a][b] > c: fee[a][b] = fee[b][a] = c
		if tim[a][b] > t: tim[a][b] = tim[b][a] = t
	for k in range(m):
		for i in range(m):
			if fee[i][k] == INF: continue
			for j in range(m):
				if fee[k][j] == INF: continue
				if fee[i][k]+fee[k][j] < fee[i][j]: fee[i][j] = fee[i][k]+fee[k][j]
				if tim[i][k]+tim[k][j] < tim[i][j]: tim[i][j] = tim[i][k]+tim[k][j]
	k = int(input())
	for i in range(k):
		p, q, r = map(int, input().split())
		if (r): print(tim[p-1][q-1])
		else:   print(fee[p-1][q-1])

Python: import heapq
def dijkstra(graph, size, start):
    distance = [float('inf')] * size
    distance[start] = 0
    que = []
    heapq.heappush(que, (0, start))
    while len(que):
        _, u = heapq.heappop(que)
        for length, vi in graph[u]:
            if distance[vi] > distance[u] + length:
                distance[vi] = distance[u] + length
                heapq.heappush(que, (distance[vi], vi))
    return distance

import sys
f = sys.stdin

import collections

while True:
    n, m = map(int, f.readline().split())
    if n == 0:
        break
    abct = [list(map(int, f.readline().split())) for _ in range(n)]
    d = [collections.defaultdict(list), collections.defaultdict(list)]
    
    for ai, bi, cost, time in abct:
        d[0][ai].append((cost, bi))
        d[0][bi].append((cost, ai))
        d[1][ai].append((time, bi))
        d[1][bi].append((time, ai))
        
    k = int(f.readline())
    
    dist = {}
    for i in range(k):
        p, q, r = map(int, f.readline().split())
        
        if (q,r) in dist:
            p, q = q, p
        elif (p,r) not in dist:
            dist[(p,r)] = dijkstra(d[r], m + 1, p)
        print(dist[(p,r)][q])