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]
					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 <map>
#define INF (int)1e9


void bellman_ford(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > &v); 

int main(void) {
    int n;
    int m;
    int a;
    int b;
    int cost;
    int time;
    int k;
    int p;
    int q;
    int r;

    while (true) {
        std::cin >> n >> m;
        if (n == 0 && m == 0) {
            break; 
        }
        std::vector<std::vector<std::pair<int, int> > > vcost(m);
        std::vector<std::vector<std::pair<int, int> > > vtime(m);
        for (int i = 0; i < n; i++) {
            std::cin >> a >> b >> cost >> time;
            --a;
            --b;
            vcost[a].push_back(std::make_pair(cost, b));
            vcost[b].push_back(std::make_pair(cost, a));
            vtime[a].push_back(std::make_pair(time, b));
            vtime[b].push_back(std::make_pair(time, a));
        }
        std::cin >> k;
        for (int i = 0; i < k; i++) {
            std::cin >> p >> q >> r;
            --p;
            --q;
            if (r == 0) {
                bellman_ford(m, p, q, vcost);
            } else {
                bellman_ford(m, p, q, vtime);
            }
        }
    } return 0;
}

void bellman_ford(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > &v) {
    std::vector<int> rvec(m, INF);
    rvec[p] = 0;
    int value;
    int target; bool flag;

    do{
        flag = false;
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < v[i].size(); j++) {
                value = v[i][j].first;
                target = v[i][j].second;
                if (rvec[target] > rvec[i] + value) {
                    rvec[target] = rvec[i] + value;
                    flag = true;
                }
            }
        }
    } while(flag);

    std::cout << rvec[q] << std::endl;
    return;
}

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

#define MAX_E 300
#define MAX_V 100
#define INF 1 << 28

struct edge {
    int to, cost;
    edge(int to, int cost) : to(to), cost(cost) {}
    void operator=(const edge& o) {
        to = o.to;
        cost = o.cost;
    }
};

typedef pair<int, int> P;

vector<edge> GTime[MAX_V];
int hour[MAX_V];
vector<edge> GMoney[MAX_V];
int money[MAX_V];
int V, E;

void shortest_path(int s) {
    priority_queue< P, vector<P>, greater<P> > q;
    fill(hour, hour+V, INF);
    fill(money, money+V, INF);
    hour[s] = 0;
    money[s] = 0;

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

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

int main() {
    while (cin >> E >> V) {
        if (E == 0 && V == 0) break;
        for (int i = 0; i < MAX_V; i++) {
            GTime[i].clear();
            GMoney[i].clear();
        }
        for (int i = 0; i < E; i++) {
            int a, b, _money, _hour;
            cin >> a >> b >> _money >> _hour;
            GTime[a-1].push_back(edge(b-1, _hour));
            GTime[b-1].push_back(edge(a-1, _hour));
            GMoney[a-1].push_back(edge(b-1, _money));
            GMoney[b-1].push_back(edge(a-1, _money));
        }
        int k; cin >> k;
        for (int i = 0; i < k; i++) {
            int from, to, qtype;
            cin >> from >> to >> qtype;
            shortest_path(from-1);
    //        for (int i = 0; i < V; i++) {
    //            cout << money[i] << ' ';
    //        } cout << endl;
    //        for (int i = 0; i < V; i++) {
    //            cout << hour[i] << ' ';
    //        } cout << endl;
    
            if (qtype == 0) {
                cout << money[to-1] << endl;
            } else {
                cout << hour[to-1] << endl;
            }
        }
    }
    return 0;
}