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 <cstdio>
#include <vector>
#include <utility>
#include <queue>
#include <functional>
#define N 101
#define INF 2000000000
using namespace std;
 
int dist[N];
typedef pair<int,int> pii;
 
std::vector<pii> e1[N];
std::vector<pii> e2[N];
 
int dijk1(int a,int b){
    dist[a]=0;
    std::priority_queue<pii> pq;
    for(int i=0;i<e2[a].size();i++){
        pq.push(e2[a][i]);
    }
    while(!pq.empty()){
        pii temp=pq.top();
        int now=temp.second;
        int c=temp.first;
        pq.pop();
        if(dist[now]!=INF)continue;
        dist[now]=c;
        if(now==b)break;
        for(int i=0;i<e2[now].size();i++){
                if(dist[e2[now][i].second]==INF) pq.push(make_pair(c+e2[now][i].first,e2[now][i].second));
        }
    }
    return -dist[b];
}
 
int dijk(int a,int b){
    dist[a]=0;
    std::priority_queue<pii> pq;
    for(int i=0;i<e1[a].size();i++){
        pq.push(e1[a][i]);
    }
    while(!pq.empty()){
        pii temp=pq.top();
        int now=temp.second;
        int c=temp.first;
        pq.pop();
        if(dist[now]!=INF)continue;
        dist[now]=c;
        if(now==b)break;
        for(int i=0;i<e1[now].size();i++){
            if(dist[e1[now][i].second]==INF) pq.push(make_pair(c+e1[now][i].first,e1[now][i].second));
        }
    }
    return -dist[b];
}
 
int main(void){
    int a,b,c,d;
    int n,m;
    while(cin>>n>>m,n||m){
        for(int i=0;i<n;i++){
            cin>>a>>b>>c>>d;
            e1[a].push_back(make_pair(-c,b));
            e2[a].push_back(make_pair(-d,b));
e1[b].push_back(make_pair(-c,a));
            e2[b].push_back(make_pair(-d,a));
        }
        int k;
        cin>>k;
        while(k--){
            for(int i=1;i<=m;i++)dist[i]=INF;
            cin>>a>>b>>c;
            if(c) cout<<dijk1(a,b)<<endl;
            else cout<<dijk(a,b)<<endl;
            // for(int i=1;i<=m;i++)printf("dist[%d]:%d\n",i,dist[i]);
        }
    }
    return 0;
}

C++: #include <algorithm>
#include <iostream>
#include <map>

using namespace std;

#define fst first
#define snd second
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
typedef pair<int,int> pii;

int n,m;
pii cost[110][110];

const int inf=1<<27;

int main(void){
	while(cin >> n >> m,n|m){
		rep(i,110)rep(j,110) cost[i][j].fst=cost[i][j].snd=((i==j)?0:inf);
		rep(i,n){
			int f,t;
			cin >> f >> t;
			f--;t--;
			cin >> cost[f][t].fst >> cost[f][t].snd;
		}

		rep(k,m)rep(i,m)rep(j,m){
			cost[i][j].fst=min(cost[i][j].fst,cost[i][k].fst+cost[k][j].fst);
			cost[i][j].snd=min(cost[i][j].snd,cost[i][k].snd+cost[k][j].snd);
		}
		int q;
		cin >> q;
		rep(i,q){
			int f,t,c;
			cin >> f >> t >> c;
			f--;t--;
			if(c)
				cout << cost[f][t].snd << endl;
			else
				cout << cost[f][t].fst << endl;
		}
	}
	return 0;
}

C++: #include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <functional>

using namespace std;

#define fst first
#define scd second
#define PB push_back
#define MP make_pair
#define chmin(a,b) a=min(a,b)
#define chmax(a,b) a=max(a,b)
#define rep(i,x) for(int i=0;i<(x);++i)
#define rep1(i,x) for(int i=1;i<=(x);++i)
#define rrep(i,x) for(int i=(x)-1;i>=0;--i)
#define rrep1(i,x) for(int i=(x);i>=1;--i)
#define FOR(i,a,x) for(int i=(a);i<(x);++i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()

template<typename T>T&get(){T a;cin >> a;return a;}
template<typename T>T&rev(T&a){reverse(all(a));return a;}
template<typename T>istream&operator>>(istream&is,vector<T>&vec){rep(i,vec.size())is>>vec[i];return is;}
template<typename T>vector<T>&sort(vector<T>a){sort(all(a));return a;}

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;

const int inf = 1e9;
const ll linf = 3e18;

struct edge {
    int to, cost, time;
    edge(int to0,int cost0,int time0) {
        to = to0; cost = cost0; time = time0;
    };
};

int N, M;

vector<edge> G[100];
int d[100];

void dijkstra(int s, int mode)
{
    priority_queue<pii, vector<pii>, greater<pii> > q;

    fill(d, d + M, inf);
    d[s] = 0;

    q.push(MP(0, s));

    while (q.size()) {
        pii p = q.top(); q.pop();
        int v = p.scd;
        rep(u, G[v].size()) {
            edge e = G[v][u];
            int a = mode == 0 ? e.cost : e.time;
            if (d[e.to] > d[v] + a) {
                d[e.to] = d[v] + a;
                q.push(MP(d[e.to], e.to));
            }
        }
    }
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    while (cin >> N >> M, N || M) {
        rep(i, M) G[i].clear();

        rep(i, N) {
            int a, b, cost, time; cin >> a >> b >> cost >> time; a--; b--;
            G[a].PB(edge(b, cost, time));
            G[b].PB(edge(a, cost, time));
        }

        int K; cin >> K;

        rep(i, K) {
            int p, q, r; cin >> p >> q >> r; p--; q--;
            dijkstra(p, r);
            cout << d[q] << endl;
        }
    }
}