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++: /* template.cpp(shinobu_menkoi) {{{ */
#include <bits/stdc++.h>
using namespace std;

// clang-format off
#define GET_MACRO(_1, _2, _3, _4, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rep1(n) rep2(_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, n) rep4(i, a, n, 1)
#define rep4(i, a, n, s) for (lint i = (a); i < (lint)(n); i += (s))
#define rrep(...) GET_MACRO(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define rrep1(a) rrep2(_, a)
#define rrep2(i, a) rrep3(i, a, 0)
#define rrep3(i, a, n) rrep4(i, a, n, 1)
#define rrep4(i, a, n, s) for (lint i = (a); i >= (lint)(n); i -= (s))
#define each(i, ctn) for (auto &&i : (ctn))

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define all(v) begin(v), end(v)
#define debug(x) cerr << (x) << " (L:" << __LINE__ << ")" << '\n'
#define TEMP_T template <class T>
#define TEMP_TU template <class T, class U>

TEMP_T using vec = vector<T>;
TEMP_T using heap = priority_queue<T>;
TEMP_T using minheap = priority_queue<T, vec<T>, greater<T>>;
using lint = long long;
using ulint = unsigned long long;
using ld = long double;
using vi = vec<int>;
using vvi = vec<vi>;
using vvvi = vec<vvi>;
using pii = pair<int, int>;
using vs = vec<string>;

TEMP_TU ostream &operator<<(ostream &os, const pair<T, U> &p) { return os << p.fi << " " << p.se; }
TEMP_TU istream &operator>>(istream &is, pair<T, U> &p) { return is >> p.fi >> p.se; }

const int INF{1001001001};
const lint LINF{1001001001001001001ll};
const int MOD{(int)1e9 + 7};
const double EPS{1e-9};
const double PI{acos(-1)};
const int dx[]{0, 1, 0, -1, 1, -1, 1, -1}, dy[]{1, 0, -1, 0, 1, -1, -1, 1};

inline bool inside(int y, int x, int h, int w) { return y >= 0 && x >= 0 && y < h && x < w; }
TEMP_T inline bool chmin(T &a, const T &b) { if (a > b) a = b; return a > b; }
TEMP_T inline bool chmax(T &a, const T &b) { if (a < b) a = b; return a < b; }
TEMP_T inline void print(const T &x) { cout << x << '\n'; }
TEMP_T inline void print(const vec<T> &v, string d = "\n") { rep(i, v.size()) cout << v[i] << (i == (lint)v.size() - 1 ? "\n" : d); }
template <class T = int> inline T in() { T x; cin >> x; return x; }
template <class T = string> vec<T> split(const string &s, char d = ',') {
  vec<T> v; stringstream ss(s); for (string b; getline(ss, b, d); ) {
    stringstream conv(b); T t; conv >> t; v.eb(t); } return v;
}
struct pre_ { pre_() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(12); } } pre__;
// clang-format on
/* }}} */

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

int dijkstra(const int& s, const int& f, const vec<vec<edge>>& G) {
  minheap<pii> q;
  int d[100];
  fill(all(d), INF);
  d[s] = 0;
  q.emplace(0, s);

  while (q.size()) {
    auto p = q.top(); q.pop();
    int v = p.second;
    if (d[v] < p.first) continue;
    each(e, G[v]) {
      if (d[e.to] > d[v] + e.cost) {
        d[e.to] = d[v] + e.cost;
        q.emplace(d[e.to], e.to);
      }
    }
  }

  return d[f];
}

signed main() {
  int n, m;
  while (cin >> n >> m, n || m) {
    vec<vec<edge>> G1(m), G2(m);
    rep(i, n) {
      int a, b, cost, time;
      cin >> a >> b >> cost >> time;
      a--; b--;
      G1[a].emplace_back(b, cost);
      G1[b].emplace_back(a, cost);
      G2[a].emplace_back(b, time);
      G2[b].emplace_back(a, time);
    }
    int k;
    cin >> k;

    rep(i, k) {
      int a, b, kind;
      cin >> a >> b >> kind;
      a--; b--;
      print(kind ? dijkstra(a, b, G2) : dijkstra(a, b, G1));
    }
  }
}

C++: #include <iostream>
#include <vector>
#include <cmath>

#define INF 100000000

using namespace std;

int main()
{
    int n, m;
    while(cin >> n >> m && n) {
        if(n == 0 || m == 0) break;
        int times[m+1][m+1], costs[m+1][m+1];
        int a,b,cost,time;
        for(int i = 1; i <= m; i++) 
            for(int j = 1; j <= m; j++) 
                times[i][j] = costs[i][j] = (i==j) ? 0 : INF; 
        
        for(int i = 0; i < n; i++) {
            cin >> a >> b >> cost >> time;
            costs[a][b] = costs[b][a] = cost;
            times[a][b] = times[b][a] = time;
        }

        for(int a = 1; a <= m; a++) {
            for(int b = 1; b <= m; b++) {
                for(int c = 1; c <= m; c++) {
                    times[a][b] = min(times[a][b], times[a][c] + times[c][b]);
                    costs[a][b] = min(costs[a][b], costs[a][c] + costs[c][b]);
                }
            }
        }

        int p,q,r,qn;
        cin >> qn;
        for(int i = 0; i < qn; i++) {
            cin >> p >> q >> r;
            if(r == 1) cout << times[p][q] << endl;
            else       cout << costs[p][q] << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
#include<algorithm>
#include<string>
#define REP(i,a) for(int  i=0;i<a;i++)
int A[101][101];
int B[101][101];
int main(){
	int a,b=0,c=0,d,n,m;	
	cin>>n>>m;
	while(n!=0||m!=0){
	REP(i,m){
		REP(j,m){
			A[i][j]=1001;
			B[i][j]=1001;
		}
	}
	REP(i,n){
	cin>>a>>b>>c>>d;
	A[a-1][b-1]=c;
	B[a-1][b-1]=d;	
	A[b-1][a-1]=c;
	B[b-1][a-1]=d;
	}
	REP(k,m){
		REP(i,m){
		if(i==k) continue;
	 		REP(j,m){
		if(i==j)continue;
		A[i][j]=min(A[i][j],A[i][k]+A[k][j]);
		B[i][j]=min(B[i][j],B[i][k]+B[k][j]);
		A[j][i]=A[i][j];
		B[j][i]=B[i][j];
			}
		}	
	}
	cin>>n;
	REP(i,n){
	cin>>a>>b>>c;
	if(c==0) cout<<A[a-1][b-1]<<endl;
	else cout<<B[a-1][b-1]<<endl;
	}
	cin>>n>>m;
	}
	return 0;
}