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 <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <functional>
#define inf 4000000
using namespace std;

int main(){
    int n, m, k;
    while(cin >> n >> m){
        if(n == 0 && m == 0) break;
        vector<vector<int>> cost(m+1,vector<int>(m+1,inf));
        vector<vector<int>> tim(m+1,vector<int>(m+1,inf));
        for(int i = 0;i<n;i++){
            int a, b;
            cin >> a >> b;
            cin >> cost[a][b] >> tim[a][b];
            cost[b][a] = cost[a][b];
            tim[b][a] = tim[a][b];
        }
        cin >> k;
        for(int i = 0;i<k;i++){
            vector<long long int> dkt(m+1,inf);
            vector<bool> checked(m+1,false);
            // priority_queue<pair<int,int>,greater<int>> pque;
            int p, q, r;
            cin >> p >> q >> r;
            dkt[p] = 0;
            // pque.push(pair<int,int>(0,p));
            while(!checked[q]){
                int top = inf, min = inf;
                for(int j = 1;j<m+1;j++){
                    if(!checked[j] && min > dkt[j]){
                        top = j;
                        min = dkt[j];
                        checked[j] = true;
                        break;
                    }
                }
                for(int j = 1;j<m+1;j++){
                    if(checked[j] || top == j) continue;
                    if(r == 0){
                        dkt[j] = std::min(dkt[j],(dkt[top]+cost[top][j]));
                    }
                    else{
                        dkt[j] = std::min(dkt[j],dkt[top]+tim[top][j]);
                    }
                }
            }
            cout << dkt[q] << endl;
        }
    }
    return 0;
}