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
			c_matrix[b-1][a-1] = c
			t_matrix[a-1][b-1] = t
			t_matrix[b-1][a-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 <functional>

constexpr int MAX_N = 100;
constexpr int INF = 100000000;

typedef std::pair<int, int> P;

struct edge {
	int to, cost;
	edge(int t, int c) : to(t), cost(c) {}
};

int n, m, K;
std::vector<edge> G[2][MAX_N];
int d[MAX_N];

void dijkstra(int s, int r) {
	std::fill(d, d + n, INF);
	d[s] = 0;
	std::priority_queue<P, std::vector<P>, std::greater<P>> que;
	que.push(P(d[s], s));

	while (!que.empty()) {
		P p = que.top(); que.pop();
		int v = p.second;
		if (p.first > d[v])
			continue;
		for (int i = 0; i < G[r][v].size(); ++i) {
			edge e = G[r][v][i];
			if (d[e.to] > d[v] + e.cost) {
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		}
	}
}

int main() {
	int a, b, c, t;
	while (1) {
		std::cin >> m >> n;
		if (m + n == 0)
			break;
		for (int i = 0; i < m; ++i) {
			std::cin >> a >> b >> c >> t;
			G[0][a - 1].push_back(edge(b - 1, c));
			G[0][b - 1].push_back(edge(a - 1, c));
			G[1][a - 1].push_back(edge(b - 1, t));
			G[1][b - 1].push_back(edge(a - 1, t));
		}
		std::cin >> K;
		int p, q, r;
		for (int i = 0; i < K; ++i) {
			std::cin >> p >> q >> r;
			dijkstra(p - 1, r);
			std::cout << d[q - 1] << std::endl;
		}
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
#define MIN(a, b) ((a)<(b)?(a):(b))
#define INF 10e6
using namespace std;
 /*temp*/

int main(){
    int n, m, l;
    while(cin>>m>>n,n){
        ll cost[n][n],time[n][n];
        // set table
        REP(i,n){
            REP(j,n){
                cost[i][j]=time[i][j]=INF;
            }
            cost[i][i]=time[i][i]=0;
        }
        // read
        REP(i,n){
            int a,b,c,t;
            cin>>a>>b>>c>>t;
            a--;
            b--;
            cost[a][b]=cost[b][a]=MIN(c,cost[a][b]);
            time[a][b]=time[b][a]=MIN(t,time[a][b]);
        }
        // Warshall???Floyd Algorithm
        REP(a,n){
            REP(b,n){
                REP(k,n){
                    cost[a][b]=cost[b][a]=MIN(cost[a][b],cost[a][k]+cost[k][b]);
                    time[a][b]=time[b][a]=MIN(time[a][b],time[a][k]+time[k][b]);
                }
            }
        }
        // 
        int q;
        cin>>q;
        REP(i,q){
            int s,d,type;
            cin>>s>>d>>type;
            s--;
            d--;
            cout<<type==0?cost[s][d]:time[s][d]<<'\n';
        }
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
typedef pair<char, int>P;

int d1[100][100];
int d2[100][100];

int main() {
	int n, m;
	while (scanf("%d%d", &n, &m), n) {
		memset(d1, 0x3f, sizeof(d1));
		memset(d2, 0x3f, sizeof(d2));
		rep(i, n) {
			int a, b, cost, time;
			scanf("%d%d%d%d", &a, &b, &cost, &time);
			a--; b--;
			d1[a][b] = d1[b][a] = cost;
			d2[a][b] = d2[b][a] = time;
		}
		rep(k, m)rep(i, m)rep(j, m) {
			d1[i][j] = min(d1[i][j], d1[i][k] + d1[k][j]);
			d2[i][j] = min(d2[i][j], d2[i][k] + d2[k][j]);
		}
		int k; scanf("%d", &k);
		rep(i, k) {
			int p, q, r;
			scanf("%d%d%d", &p, &q, &r);
			p--; q--;
			if (r)printf("%d\n", d2[p][q]);
			else printf("%d\n", d1[p][q]);
		}
	}
	return 0;
}