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<iostream>
#include<vector>
#include<queue>
using namespace std;

class S{
public:
	S(int pos,int cost){
		p=pos;
		c=cost;
	}
	int p,c;
};
bool operator<(S a,S b){
	return a.c>b.c;
}
int m;
vector<S> edge[100][2];
void add_edge(int a,int b,int c,int t){
	edge[a][0].push_back(S(b,c));
	edge[a][1].push_back(S(b,t));
	edge[b][0].push_back(S(a,c));
	edge[b][1].push_back(S(a,t));
}


int solve(int p,int q,int r){
	int ans=0;
	bool use[100];
	for(int i=0;i<100;i++){
		use[i]=0;
	}
	
	priority_queue<S> que;
	que.push(S(p,0));
	
	while(!que.empty()){
		S n=que.top();que.pop();
		
		if(use[n.p]){
			continue;
		}
		use[n.p]=1;
		
		if(n.p==q){
			ans=n.c;
			break;
		}
		
		for(int i=0;i<edge[n.p][r].size();i++){
			if(!use[edge[n.p][r][i].p]){
				que.push(S(edge[n.p][r][i].p,n.c+edge[n.p][r][i].c));
			}
		}
	}
	return ans;
}



int main(){
	int n;
	while(cin>>n>>m,n!=0||m!=0){
		for(int i=0;i<n;i++){
			int a,b,c,t;
			cin>>a>>b>>c>>t;
			a--;b--;
			add_edge(a,b,c,t);
		}
		int k;
		cin>>k;
		for(int i=0;i<k;i++){
			int p,q,r;
			cin>>p>>q>>r;
			p--;q--;
			cout<<solve(p,q,r)<<endl;
		}
	}
}

C++: #include <iostream>

#define INFINITY (1001)

using namespace std;

int main(void)
{
	int time[300][300];
	int cost[300][300];
	int req[3][100];
	int n, m;
	while (1){
	
	cin >> n >> m;
	if (n == 0 && m == 0){
		break;
	}
	for (int i = 0; i < m; i++){
		for (int j = 0; j < m; j++){
			time[i][j] = cost[i][j] = INFINITY;
		}
	}
	for (int i = 0; i < n; i++){
		int a, b, t, c;
		cin >> a >> b >> c >> t;
		time[a - 1][b - 1] = time[b - 1][a - 1] = t;
		cost[a - 1][b - 1] = cost[b - 1][a - 1] = c;
	}
	
	for (int k = 0; k < m; k++){
		for (int i = 0; i < m; i++){
			for (int j = 0; j < m; j++){
				time[i][j] = min(time[i][j], time[i][k] + time[k][j]);
				cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
			}
		}
	}
	
	
	int req_count;
	cin >> req_count;
	for (int i = 0; i < req_count; i++){
		cin >> req[0][i] >> req[1][i] >> req[2][i];
	}
	
	for (int i = 0; i < req_count; i++){
		if (req[2][i] == 0){
			cout << cost[req[0][i] - 1][req[1][i] - 1] << endl;
		}
		else {
			cout << time[req[0][i] - 1][req[1][i] - 1] << endl;
		}
	}
	}
	return (0);
}

C++: # include <iostream>
# include <vector>
# include <queue>
# include <functional>

constexpr int MAX_N = 100;
constexpr int INF = 100000000;

typedef std::pair<int, int> P;

struct edge {
	int to, cost;
	edge(int t, int c) : to(t), cost(c) {}
};

int n, m, K;
std::vector<edge> G[2][MAX_N];
int d[MAX_N];

void dijkstra(int s, int r) {
	std::fill(d, d + n, INF);
	d[s] = 0;
	std::priority_queue<P, std::vector<P>, std::greater<P>> que;
	que.push(P(d[s], s));

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

int main() {
	int a, b, c, t;
	while (1) {
		std::cin >> m >> n;
		if (m + n == 0)
			break;

		for (int i = 0; i < 2; ++i) {
			for (int j = 0; j < n; ++j)
				G[i][j].clear();
		}

		for (int i = 0; i < m; ++i) {
			std::cin >> a >> b >> c >> t;
			G[0][a - 1].push_back(edge(b - 1, c));
			G[0][b - 1].push_back(edge(a - 1, c));
			G[1][a - 1].push_back(edge(b - 1, t));
			G[1][b - 1].push_back(edge(a - 1, t));
		}
		std::cin >> K;
		int p, q, r;
		for (int i = 0; i < K; ++i) {
			std::cin >> p >> q >> r;
			dijkstra(p - 1, r);
			std::cout << d[q - 1] << std::endl;
		}
	}
	return 0;
}