Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

const INF = 0x7FFFFFFF

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
				} else {
					c_dist[i][j] = c_matrix[i][j]
				}
				if c_matrix[i][j] == 0{
					c_prev[i][j] = -1
				} else {
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0{
					t_dist[i][j] = INF
				} else {
					t_dist[i][j] = t_matrix[i][j]
				}
				if t_matrix[i][j] == 0{
					t_prev[i][j] = -1
				} else {
					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]
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[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 <bits/stdc++.h>
#include<stdio.h>
using namespace std;
#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(a) begin(a),end(a)
#define MS(m,v) memset(m,v,sizeof(m))
#define D10  fixed<<setprecision(10)
typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int, int> P;
typedef long long ll;
const ll INF = 114514810;
const ll MOD = 1000000007;
const double EPS = 1e-8;
const double PI = acos(-1.0);
struct edge
{
	int from, to, cost;
	bool operator < (const edge& e) const { return cost < e.cost; }
	bool operator >(const edge& e) const { return cost > e.cost; }
};
int dx[] = { -1, 0, 0, 1 }; int dy[] = { 0, -1, 1, 0 };
bool valid(int x, int y, int h, int w) { return (x >= 0 && y >= 0 && x < h&&y < w); }
///*************************************************************************************///
///*************************************************************************************///
///*************************************************************************************///


int main()
{
	int n, m;
	while (cin >> n >> m, n)
	{
		int tim[101][101], cos[101][101];
		REP(i, m)REP(j, m) tim[i][j] = (i == j ? 0 : INF);
		REP(i, m)REP(j, m) cos[i][j] = (i == j ? 0 : INF);
		while (n--)
		{
			int a, b, c, d;
			cin >> a >> b >> c >> d;
			a--; b--;
			tim[a][b] = tim[b][a] = c;
			cos[a][b] = cos[b][a] = d;
		}
		REP(k, m)REP(i, m)REP(j, m) tim[i][j] = min(tim[i][j], tim[i][k] + tim[k][j]);
		REP(k, m)REP(i, m)REP(j, m) cos[i][j] = min(cos[i][j], cos[i][k] + cos[k][j]);
		int q;
		cin >> q;
		while (q--)
		{
			int a, b, c;
			cin >> a >> b >> c;
			a--; b--;
			cout << (c == 0 ? tim[a][b] : cos[a][b]) << endl;
		}
	}
}

C++: #include <iostream>
#include <algorithm>
#include <utility>
#include <vector>

const int INF = 1000000;

using Mat = std::vector< std::vector<int> >;

void wf(Mat& adj_mat) {
  int n = adj_mat.size();

  for(int i = 0; i < n; ++i) {     // via node
    for(int j = 0; j < n; ++j) {   // start
      for(int k = 0; k < n; ++k) { // terminal
        adj_mat[j][k] = std::min(adj_mat[j][k], adj_mat[j][i] + adj_mat[i][k]);
      }
    }
  }
}

int main() {
  int n, m;
  int a, b, cost, time;

  std::cin >> n >> m;
  Mat cost_table, time_table;
  cost_table.resize(m);
  time_table.resize(m);
  for(int i = 0; i < m; ++i) {
    cost_table.at(i).resize(m);
    time_table.at(i).resize(m);
    for(int j = 0; j < m; ++j){
      cost_table[i][j] = INF;
      time_table[i][j] = INF;
    }
  }

  for(int i = 0; i < n; ++i){
    std::cin >> a >> b >> cost >> time;
    --a, --b;
    cost_table[a][b] = cost_table[b][a] = cost;
    time_table[a][b] = time_table[b][a] = time;
  }

  wf(cost_table);
  wf(time_table);

  // Query
  int k;
  int p, q, r;
  std::cin >> k;
  for(int i = 0; i < k; ++i){
    std::cin >> p >> q >> r;
    --p, --q;
    if (r == 0)
      std::cout << cost_table[p][q] << std::endl;
    else
      std::cout << time_table[p][q] << std::endl;

  }
}

C++: #include <iostream>
#include <cctype>
#include <algorithm>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <utility>
#include <string>
#include <functional>
#include <cctype>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
typedef long long ll;
const int INF = 100000000, mod = 1000000007;
const ll LLINF = 1LL << 50;
using namespace std;

struct edge { int to, cos, tim; };
typedef pair<int, int> P;
vector<edge> G[105];
ll n, m, k, cost[105], ti[105];

void dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> costque, timeque;
    fill(cost, cost + m + 1, INF);
    fill(ti, ti + m + 1, INF);
    cost[s] = 0;
    ti[s] = 0;
    costque.push(P(s, 0));
    timeque.push(P(s, 0));

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

int main() {
    while (1) {
        cin >> n >> m;
        if (n == 0 && m == 0) break;
        for (int i = 0; i < n; i++) {
            int a, b, c, t;
            cin >> a >> b >> c >> t;
            edge tmp = { b,c,t };
            G[a].push_back(tmp);
        }
        cin >> k;
        for (int i = 0; i < k; i++) {
            int p, q, r;
            cin >> p >> q >> r;
            dijkstra(p);
            if (r == 0) cout << cost[q] << endl;
            else cout << ti[q] << endl;
        }
    }
    return 0;
}