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
			c_matrix[b-1][a-1] = c
			t_matrix[a-1][b-1] = t
			t_matrix[b-1][a-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++: #include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <utility>
#include <ctime>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <cstring>
#include <vector>
#include <algorithm>
#include <functional>
#include <fstream>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <cstring>
#include <numeric>
#include <cassert>
using namespace std;
#define rep(i, n) for (int(i) = 0; (i) < (n); (i)++)
class Timer
{
  private:
    double time_limit;
    //unsigned long long int cycle_per_sec = 2500000000; // Topcoder
    unsigned long long int cycle_per_sec = 2777777777; // AtCoder
    unsigned long long int beginCycle;
    unsigned long long int getCycle()
    {
        unsigned int low, high;
        __asm__ volatile("rdtsc"
                         : "=a"(low), "=d"(high));
        return ((unsigned long long int)low) | ((unsigned long long int)high << 32);
    }

  public:
    Timer(double time_limit) : time_limit(time_limit)
    {
        beginCycle = getCycle();
    }

    double elapsedTime()
    {

        return (double)(getCycle() - beginCycle) / cycle_per_sec;
    }
    bool isTLE()
    {
        return elapsedTime() >= time_limit;
    }
};

Timer gtimer(2.85);

int main()
{
    int m, n;
    while (cin >> m >> n && m)
    {
        int wf[2][310][310] = {};
        rep(i, 2) rep(j, 310) rep(k, 310)
            wf[i][j][k] = j == k ? 0 : 1e9;

        for (int i = 0; i < m; i++)
        {
            int a, b, c, t;
            cin >> a >> b >> c >> t;
            --a, --b;
            wf[0][a][b] = min(wf[0][a][b], c);
            wf[1][a][b] = min(wf[1][a][b], t);
        }
        rep(i, 2)
        {
            rep(j, 310) rep(k, 310) rep(l, 310)
            {
                wf[i][k][l] = min(wf[i][k][j] + wf[i][j][l], wf[i][k][l]);
            }
        }
        int Q;
        cin >> Q;
        while (Q--)
        {
            int a, b, c;
            cin >> a >> b >> c;
            --a, --b;
            cout << wf[c][a][b] << endl;
        }
    }
    std::cout.flush();
    return 0;
}

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] ;
int TimeAns [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 ) ;
		}
		Dijkstra ( 1 , m , 0 ) ;
		Dijkstra ( 1 , m , 1 ) ;
		int Q ;
		scanf ( "%d" , &Q ) ;
		while ( Q-- )
		{
			int p ;
			int q ;
			int r ;
			scanf ( "%d %d %d" , &p , &q , &r ) ;
			if ( r == 0 )
			{
				if ( p == 1 )
				{
					printf ( "%d\n" , CostAns[q] ) ;
				}
				else
				{
					printf ( "%d\n" , CostAns[q] - CostAns[p] ) ;
				}
			}
			else
			{
				if ( p == 1 )
				{
					printf ( "%d\n" , TimeAns[q] ) ;
				}
				else
				{
					printf ( "%d\n" , TimeAns[q] - TimeAns[p] ) ;
				}
			}
		}
	}
	return 0 ;
}

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

void Dijkstra ( int source , int m , int type )
{
	memset ( vis , false , 110 * sizeof ( bool ) ) ;
	priority_queue < struct Node > pQ ;
	if ( type == 0 )
	{
		TimeAns[source] = 0 ;
	}
	else
	{
		CostAns[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[*it] == -1 || ( TimeAns[*it] > var.C + *( iu ) ) )
					{
						TimeAns[*it] = var.C + *( iu ) ;
						pQ.push ( Node ( *it , TimeAns[*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[*it] == -1 || ( CostAns[*it] > var.C + *( iu ) ) )
					{
						CostAns[*it] = var.C + *( iu ) ;
						pQ.push ( Node ( *it , CostAns[*it] ) ) ;
					}
				}
			}
		}
	}
}