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<bits/stdc++.h>
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vii;
#define rrep(i, m, n) for(int (i)=(m); (i)<(n);  (i)++)
#define  rep(i, n)    for(int (i)=0; (i)<(n);  (i)++)
#define  rev(i, n)    for(int (i)=(n)-1; (i)>=0; (i)--)
#define vrep(i, c)    for(__typeof((c).begin())i=(c).begin(); i!=(c).end(); i++)
#define  ALL(v)       (v).begin(), (v).end()
#define mp            make_pair
#define pb            push_back
template<class T1, class T2> inline void minup(T1& m, T2 x){ if(m>x) m=static_cast<T2>(x); }
template<class T1, class T2> inline void maxup(T1& m, T2 x){ if(m<x) m=static_cast<T2>(x); }

#define INF 1000000000LL
#define MOD 1000000009
#define EPS 1E-9

const int MAX_V = 1000;
ll dp[2][MAX_V][MAX_V];
int E, V;
int a, b;
ll c, t;
int k;
int p, q, r;

int main()
{
  while((cin >> E >> V) && E && V){
    rep(i, V) rep(j, V) dp[0][i][j] = dp[1][i][j] = INF;

    rep(i, E){
      cin >> a >> b >> c >> t;
      a-=1;  b-=1;
      dp[0][a][b] = dp[0][b][a] = c;
      dp[1][a][b] = dp[0][b][a] = t;
    }

    rep(b, 2) rep(k, V) rep(i, V) rep(j, V) minup(dp[b][i][j], dp[b][i][k] + dp[b][k][j]);

    cin >> k;
    while(k--){
      cin >> p >> q >> r;
      cout << dp[r][p-1][q-1] << endl;
    }
  }

  return 0;
}

C++: #include <cstdio>
#include <vector>

using namespace std;

class Edge{
public:
	int from,to,cost,time;
	void Swap(){
		int self = from;
		from = to;
		to = from;
	}
	int GetValue(int r){
		if(r == 0){
			return cost;
		}else{
			return time;
		}
	}
};

vector<Edge> edge;
int n,m;

const int INF = 100000000;

int solve(const int p,const int q,const int r);

int main(){
	scanf("%d %d",&n,&m);
	for(int i=0;i<n;i++){
		Edge ed;
		scanf("%d %d %d %d",&ed.from,&ed.to,&ed.cost,&ed.time);
		edge.push_back(ed);
		ed.Swap();
		edge.push_back(ed);
	}
	int k;
	int p,q,r;
	scanf("%d",&k);
	for(int i=0;scanf("%d %d",&p,&q) && p && q && i < k;i++){
		scanf("%d",&r);
		printf("%d\n",solve(p,q,r));
	}
	return 0;
}

int solve(const int p,const int q,const int r){
	vector<int> d(m+1);
	for(int i=0;i<=m;i++){
		d[i] = INF;
	}
	d[p] = 0;
	
	bool flag;
	while(1){
		flag = false;
		vector<Edge>::iterator it;
		for(it = edge.begin();it != edge.end();it++){
			if(d[(*it).from] != INF && d[(*it).to] > d[(*it).from] + (*it).GetValue(r)){
				d[(*it).to] = d[(*it).from] + (*it).GetValue(r);
				flag = true;
			}
		}
		if(!flag){
			break;
		}
	}
	
	return d[q];
}

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);
}