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++: 
#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;
		}

		int N,p,q,r;
		int dt[100][100];
		int dc[100][100];
		for(int i=0;i<m;i++){
			for(int j=0;j<m;j++){
				dt[i][j]=T[i][j];
			}
		}
		for(int k=0;k<m;k++){
			for(int i=0;i<m;i++){
				for(int j=0;j<m;j++){
					if(dt[i][j]>dt[i][k]+dt[k][j]){
						dt[i][j]=dt[i][k]+dt[k][j];
					}
				}
			}
		} 
		for(int i=0;i<m;i++){
			for(int j=0;j<m;j++){
				dc[i][j]=C[i][j];
			}
		}
		for(int k=0;k<m;k++){
			for(int i=0;i<m;i++){
				for(int j=0;j<m;j++){
					if(dc[i][j]>dc[i][k]+dc[k][j]){
						dc[i][j]=dc[i][k]+dc[k][j];
					}
				}
			}
		} 
		cin >> N;
		for(int I=0;I<N;I++){
			cin >> p >> q >> r;
			cout << (r?dt[p-1][q-1]:dc[p-1][q-1]) << endl;
		}
		
		/*
		int k,p,q,r;
		cin >> k;
		for(int I=0;I<k;I++){
			int d[m];
			bool u[m];
			cin >> p >> q >> r;
			for(int i=0;i<m;i++){
				d[i] = INF;
				u[i] = false;
			}
			d[p-1]=0;

			while(1){
				int v = -1;
				for(int i=0;i<m;i++){
					if(u[i])continue;
					if(v==-1||d[i]<d[v]){
						v = i;
					}
				}
				if(v==-1)break;
				u[v]=true;

				for(int i=0;i<m;i++){
					if(r){
						if(d[i]>d[v]+T[v][i]){
							d[i]=d[v]+T[v][i];
						}
					}else{
						if(d[i]>d[v]+C[v][i]){
							d[i]=d[v]+C[v][i];
						}
					}
				}
			}
		
			cout << d[q-1] << endl;
		}*/		
	}

	return 0;
}

C++: #include <iostream>

using namespace std;

static const int TYPE_COST =0;
static const int TYPE_TIME =1;
static const int INF =100000000;
static const int MAX_N = 300;
static const int MAX_M = 100;
int C[MAX_M][MAX_M];
int T[MAX_M][MAX_M];

void init(int type, int n);

int main(int argc, char** argv)
{
	while( 1 ){
		int n, m, from, to, c, t, type;
		cin >> n;
		cin >> m;
		if(n==0 && m==0) break;
		init(TYPE_COST, m);
		init(TYPE_TIME, m);
		for(int i=0; i<n; i++)
		{
			cin >> from;
			cin >> to;
			cin >> c;
			cin >> t;
			C[from-1][to-1] = C[to-1][from-1] = c;
			T[from-1][to-1] = T[to-1][from-1] = t;
		}
		
		for(int k=0; k<m; k++){
			for(int i=0; i<m; i++){
				for(int j=0; j<m; j++){
					C[i][j] = min(C[i][j], C[i][k] + C[k][j]);
					T[i][j] = min(T[i][j], T[i][k] + T[k][j]);
				}
			}
		}
		
		cin >> m;
		for(int i=0; i<m; i++){
			cin >> from;
			cin >> to;
			cin >> type;
			if(type == TYPE_COST) cout << C[from-1][to-1] << endl;
			if(type == TYPE_TIME) cout << T[from-1][to-1] << endl;
		}
	}
	
	return 0;
}

void init(int type, int n)
{
	if(type==TYPE_COST){
		for(int i=0; i<n; i++)
		{
			for(int j=0; j<n; j++)
			{
				if(i==j) C[i][j] = 0;
				else C[i][j] = INF;
			}
		}
	}
	
	if(type==TYPE_TIME){
		for(int i=0; i<n; i++)
		{
			for(int j=0; j<n; j++)
			{
				if(i==j) T[i][j] = 0;
				else T[i][j] = INF;
			}
		}
	}
}