Go: // Warshall–Floyd Algorithm

package main

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

var scanner = bufio.NewScanner(os.Stdin)

const INF = 2000000000

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])
			}
		}
	}
}

C++: #include<stack>
#include<queue>
#include<vector>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
static const int INFTY = (1 << 21);
int main(){
	int n, m, a, b, cost, time;
	int kk, p, q, r;
	int sta_c[100][100];
	int sta_t[100][100];
	while (cin >> n >> m, n, m){
		for (int i = 0; i < 100; i++){
			for (int j = 0; j < 100; j++){
				sta_c[i][j] = sta_t[i][j] = INFTY;
			}
		}
		for (int i = 0; i < n; i++){
			cin >> a >> b >> cost >> time;
			sta_c[a][b] = cost; sta_c[b][a] = cost;
			sta_t[a][b] = time; sta_t[b][a] = time;
		}
		for (int k = 1; k <= m; k++){
			for (int i = 1; i <= m; i++){
				if (sta_c[i][k] == INFTY) continue;
				for (int j = 1; j <= m; j++){
					if (sta_c[k][j] == INFTY) continue;
					sta_c[i][j] = min(sta_c[i][j], sta_c[i][k] + sta_c[k][j]);
					sta_t[i][j] = min(sta_t[i][j], sta_t[i][k] + sta_t[k][j]);
				}
			}
		}
		cin >> kk;
		for (int i = 0; i < kk; i++){
			cin >> p >> q >> r;
			if (r == 0) cout << sta_c[p][q] << endl;
			else cout << sta_t[p][q] << endl;
		}
	}
	return 0;
}

C++: #include <algorithm>
#include <cstdlib>
#include <iostream>
#include <vector>


template <typename T> using Distance = std::vector<std::vector<T>>;
constexpr int INF = 100000000;


template <typename T> void in_place_init_dist(int num_vertices, Distance<T>& dist) {
	for (auto i = 0; i < num_vertices; i++) {
		for (auto j = 0; j < num_vertices; j++)
		{
			if (i == j)
			{
				dist[i][j] = 0;
			}
			else
			{
				dist[i][j] = INF;
			}
		}
	}
}


template <typename T> void in_place_warshall_floyd(int num_vertices, Distance<T>& dist) {
	for (auto k = 0; k < num_vertices; k++)
	{
		for (auto i = 0; i < num_vertices; i++)
		{
			for (auto j = 0; j < num_vertices; j++)
			{
				dist[i][j] = std::min(dist[i][j], dist[i][k] + dist[k][j]);
			}
		}
	}
}


int main() {
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	while (true)
	{
		int n, m;
		std::cin >> n >> m;
		if (n == 0 && m == 0)
		{
			break;
		}
		Distance<int> cost;
		Distance<int> time;
		cost = Distance<int>(m, std::vector<int>(m, 0));
		time = Distance<int>(m, std::vector<int>(m, 0));
		in_place_init_dist(m, cost);
		in_place_init_dist(m, time);
		int a, b, c, t;
		for (auto i = 0; i < n; i++)
		{
			std::cin >> a >> b >> c >> t;
			a--;
			b--;
			cost[a][b] = c;
			cost[b][a] = c;
			time[a][b] = t;
			time[b][a] = t;
		}
		in_place_warshall_floyd(m, cost);
		in_place_warshall_floyd(m, time);
		int k, p, q, r;
		std::cin >> k;
		for (auto i = 0; i < k; i++)
		{
			std::cin >> p >> q >> r;
			p--;
			q--;
			std::cout << (r == 0 ? cost[p][q] : time[p][q]) << std::endl;
		}
	}

	return EXIT_SUCCESS;
}

C++: // 2014/06/16 Tazoe

#include <iostream>
using namespace std;

const int INF = 1000000000;

int main()
{
	while(true){
		int n, m;
		cin >> n >> m;

		if(n==0 && m==0)
			break;

		int C[100][100];
		int T[100][100];
		for(int i=0; i<m; i++){
			for(int j=0; j<m; j++){
				if(i==j){
					C[i][j] = T[i][j] = 0;
				}
				else{
					C[i][j] = T[i][j] = INF;
				}
			}
		}

		for(int i=0; i<n; i++){
			int a, b, c, t;
			cin >> a >> b >> c >> t;

			C[a-1][b-1] = C[b-1][a-1] = c;
			T[a-1][b-1] = T[b-1][a-1] = t;
		}
    for(int k=0;k<m;k++){
      for(int i=0;i<m;i++){
        for(int j=0;j<m;j++){
          if(C[i][j] > C[i][k]+C[k][j])
            C[i][j] = C[i][k] + C[k][j];
          if(T[i][j] > T[i][k]+T[k][j])
            T[i][j] = T[i][k] + T[k][j];
        }
      }
    }
    unsigned int k;
    cin >> k;
    for(int i=0;i<k;i++){
      int p,q,r;
      cin >> p >> q;

      cin >> r;

      if(r==0){
        cout << C[p-1][q-1] << endl;
      } else {
        cout << T[p-1][q-1] << endl;
      }
    }
    break;
  }

	return 0;
}