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 <stdio.h>
#include <string.h>
#include <queue>
#include <vector>
#include <algorithm>

using namespace std ;

struct Node
{
	int P ;
	int C ;
	Node ( ) { }
	Node ( int a , int b )
	{
		P = a ;
		C = b ;
	}
	bool operator < ( const Node &a ) const
	{
		return C > a.C ;
	}
} ;

vector < int > ListofRoad [110] ;
vector < int > ListofTime [110] ;
vector < int > ListofCost [110] ;

int CostAns[110][110] ;
int TimeAns[110][110] ;
bool vis[110] ;

void init ( ) ;
void Dijkstra ( int , int , int ) ;

int main ( )
{
	int n ;
	int m ;
	while ( scanf ( "%d %d" , &n , &m ) == 2 && ( n || m ) )
	{
		init ( ) ;
		for ( int i = 0 ; i < n ; i++ )
		{
			int a ;
			int b ;
			int c ;
			int d ;
			scanf ( "%d %d %d %d" , &a , &b , &c , &d ) ;
			ListofRoad[a].push_back ( b ) ;
			ListofCost[a].push_back ( c ) ;
			ListofTime[a].push_back ( d ) ;
			ListofRoad[b].push_back ( a ) ;
			ListofCost[b].push_back ( c ) ;
			ListofTime[b].push_back ( d ) ;
		}
		int Q ;
		scanf ( "%d" , &Q ) ;
		while ( Q-- )
		{
			int p ;
			int q ;
			int r ;
			scanf ( "%d %d %d" , &p , &q , &r ) ;
			if ( r == 0 )
			{
				if ( CostAns[p][q] == -1 )
				{
					Dijkstra ( p , m , 1 ) ;
				}
				printf ( "%d\n" , CostAns[p][q] ) ;
			}
			else
			{
				if ( TimeAns[p][q] == -1 )
				{
					Dijkstra ( p , m , 0 ) ;
				}
				printf ( "%d\n" , TimeAns[p][q] ) ;
			}
		}
	}
	return 0 ;
}

void init ( )
{
	for ( int i = 0 ; i < 110 ; i++ )
	{
		ListofRoad[i].clear ( ) ;
		ListofTime[i].clear ( ) ;
		ListofCost[i].clear ( ) ;
	}
	memset ( CostAns , -1 , 110 * 110 * sizeof ( int ) ) ;
	memset ( TimeAns , -1 , 110 * 110 * sizeof ( int ) ) ;
}

void Dijkstra ( int source , int m , int type )
{
	memset ( vis , false , 110 * sizeof ( bool ) ) ;
	priority_queue < struct Node > pQ ;
	if ( type == 0 )
	{
		TimeAns[source][source] = 0 ;
	}
	else
	{
		CostAns[source][source] = 0 ;
	}
	pQ.push ( Node ( source , 0 ) ) ;
	for ( int i = 1 ; i <= m ; i++ )
	{
		struct Node var = ( struct Node ) { -1 , -1 } ;
		while ( pQ.empty ( ) == false && vis[( var = pQ.top ( ) ).P] == true )
		{
			pQ.pop ( ) ;
		}
		if ( var.P == -1 )
		{
			break ;
		}
		vis[var.P] = true ;
		if ( type == 0 )
		{
			vector < int > :: iterator iu = ListofTime[var.P].begin ( ) ;
			for ( vector < int > :: iterator it = ListofRoad[var.P].begin ( ) ;
				it != ListofRoad[var.P].end ( ) ;
				it++ , iu++ )
			{
				if ( vis[*it] == false )
				{
					if ( TimeAns[source][*it] == -1 || ( TimeAns[source][*it] > var.C + *( iu ) ) )
					{
						TimeAns[source][*it] = var.C + *( iu ) ;
						pQ.push ( Node ( *it , TimeAns[source][*it] ) ) ;
					}
				}
			}
		}
		else
		{
			vector < int > :: iterator iu = ListofCost[var.P].begin ( ) ;
			for ( vector < int > :: iterator it = ListofRoad[var.P].begin ( ) ;
				it != ListofRoad[var.P].end ( ) ;
				it++ , iu++ )
			{
				if ( vis[*it] == false )
				{
					if ( CostAns[source][*it] == -1 || ( CostAns[source][*it] > var.C + *( iu ) ) )
					{
						CostAns[source][*it] = var.C + *( iu ) ;
						pQ.push ( Node ( *it , CostAns[source][*it] ) ) ;
					}
				}
			}
		}
	}
}

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;
}