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++: // clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define forever for (;;)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
typedef std::pair<int, int> pii;
typedef std::vector<int> vi;
typedef std::vector<double> vd;
typedef std::vector<std::string> vs;
typedef std::vector<pii> vpii;
typedef std::vector<vi> vvi;
typedef std::vector<vpii> vvpii;
const int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
const int MOD = 1000000007;
const double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
template<typename T> std::istream &operator>>(std::istream &is, std::vector<T> &v) { rep(i,v.size()) is >> v[i]; return is; }
template<typename A, typename B> std::istream &operator>>(std::istream &is, std::pair<A, B> &p) { is >> p.first; is >> p.second; return is; }
using namespace std;
// clang-format on

typedef int Weight;
struct Edge {
  int src, dst;
  Weight weight;
  Edge(const int &s = 0, const int &d = 0, const Weight &w = 0) : src(s), dst(d), weight(w) {}
};

typedef std::vector<Edge> Edges;
typedef std::vector<Weight> Array;
typedef std::vector<Array> Matrix;

class Graph {
  std::vector<Edges> g;

public:
  Graph(const int &size = 0) : g(size) {}
  int size() const { return g.size(); }
  const Edges &operator[](const int &i) const { return g[i]; }
  void addArc(const int &src, const int &dst, const Weight &w = 1) { g[src].emplace_back(src, dst, w); }
  void addEdge(const int &node1, const int &node2, const Weight &w = 1) {
    addArc(node1, node2, w);
    addArc(node2, node1, w);
  }
};

template<int inf = std::numeric_limits<Weight>::max() / 8> std::pair<std::vector<Weight>, std::vector<int>> dijkstra(const Graph &g, const int &src) {
  using state = std::pair<Weight, int>;
  std::priority_queue<state, std::vector<state>, std::greater<state>> q;
  std::vector<Weight> dist(g.size(), inf);
  std::vector<int> via(g.size());
  dist[src] = 0;
  q.emplace(0, src);
  while (q.size()) {
    Weight d;
    int v;
    std::tie(d, v) = q.top();
    q.pop();
    if (dist[v] < d) continue;
    for (auto &e : g[v]) {
      if (cmin(dist[e.dst], dist[v] + e.weight)) {
        via[e.dst] = v;
        q.emplace(dist[e.dst], e.dst);
      }
    }
  }
  return {dist, via};
}

main {
  int n, m;
  while (cin >> n >> m, n) {
    Graph g1(m), g2(m);
    while (n--) {
      int a, b, cost, time;
      cin >> a >> b >> cost >> time;
      --a, --b;
      g1.addEdge(a, b, cost);
      g2.addEdge(a, b, time);
    }
    Matrix dist1(m, Array(m)), dist2(m, Array(m));
    rep(i, m) {
      vector<Weight> d1 = dijkstra(g1, i).first, d2 = dijkstra(g2, i).first;
      rep(j, m) {
        dist1[i][j] = d1[j];
        dist2[i][j] = d2[j];
      }
    }
    int k;
    cin >> k;
    while (k--) {
      int p, q, r;
      cin >> p >> q >> r;
      --p, --q;
      cout << (r ? dist2[p][q] : dist1[p][q]) << endl;
    }
  }
}

C++: #include<iostream>
#include<vector>
#include<queue>
using namespace std;

#define INF 100000000

struct edge {
	int to;
	int c, t;
};

int main() {
	int n, m, f, temp, s, k, p, q, r;
	vector<edge> g[101];
	queue<int> search;
	int mc[101][101], mt[101][101];
	edge e;
	cin >> n >> m;
	for(int i=0; i<=m; ++i) for(int j=0; j<=m; ++j) {
		mc[i][j] = mt[i][j] = INF;
	}
	for(int i=0; i<n; ++i) {
		cin >> f >> e.to >> e.c >> e.t;
		g[f].push_back(e);
		temp = e.to; e.to = f; f = temp;
		g[f].push_back(e);
	}
	for(int i=1; i<=m; ++i) {
		search.push(i); mc[i][i] = 0;
		while(!search.empty()) {
			s = search.front(); search.pop();
			for(vector<edge>::iterator it=g[s].begin(); it!=g[s].end(); ++it) {
				if(mc[i][s]+(*it).c<mc[i][(*it).to]) {
					mc[i][(*it).to] = mc[i][s]+(*it).c;
					search.push((*it).to);
				}
			}
		}
		search.push(i); mt[i][i] = 0;
		while(!search.empty()) {
			s = search.front(); search.pop();
			for(vector<edge>::iterator it=g[s].begin(); it!=g[s].end(); ++it) {
				if(mt[i][s]+(*it).t<mt[i][(*it).to]) {
					mt[i][(*it).to] = mt[i][s]+(*it).t;
					search.push((*it).to);
				}
			}
		}
	}
	cin >> k;
	for(int i=0; i<k+1; ++i) {
		cin >> p >> q;
		if(!p&&!q) break;
		cin >> r;
		cout << (!r?mc[p][q]:mt[p][q]) << endl;
	}
	
	return 0;
}

C++: #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];
					}
				}
			}
		}

		for(int k=0; k<m; k++){
			for(int i=0; i<m; i++){
				for(int j=0; j<m; j++){
					if(T[i][j]>T[i][k]+T[k][j]){
						T[i][j]=T[i][k]+T[k][j];
					}
				}
			}
		}
		int i,p[i],q[i],r[i],k;
		cin>>k;
		for( i=0; i<k; i++){
			cin>>p[i]>>q[i]>>r[i];
			
	
			int P=p[i],Q=q[i],R=r[i];	
			if(R==0){
				cout<<C[P-1][Q-1]<<endl;
			}
			else{
				cout<<T[P-1][Q-1]<<endl;
			}
		}
	}
		
		
return 0;
}