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>
#include <vector>
using namespace std;

struct edge {
    int from, to, cost, time;
};

int main() {
    int n, m, a, b, cost, time, k, p, q, r;
    while (cin >> n >> m, n || m) {
        vector<edge> edges;
        for (int i=0; i<n; ++i) {
            cin >> a >> b >> cost >> time;
            edges.push_back((edge){ a, b, cost, time });
        }
        cin >> k;
        for (int i=0; i<k; ++i) {
            cin >> p >> q >> r;
            int d[100];
            for (int i=0; i<100; ++i) d[i] = 1e8;
            d[p] = 0;
            for (int i=0; i<100; ++i) {
                for (int j=0; j<(int)edges.size(); ++j) {
                    edge &e = edges[j];
                    if (r == 0) {
                        d[e.to] = min(d[e.to], d[e.from] + e.cost);
                    } else {
                        d[e.to] = min(d[e.to], d[e.from] + e.time);
                    }
                }
            }
            cout << d[q] << endl;
        }
    }
    return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<vector>
#include<string>
#include<queue>
#include<map>

using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define reps(i,n) for(int i=1;i<=n;i++)

#define INF 1000000000

int main(){
	while(1){
		int n,m;
		cin>>n>>m;
		
		if(n==0 && m==0)break;
		
		int dp[111][111][2];
		rep(p,2){
		rep(i,111)rep(j,111){
			dp[i][j][p]=INF;
		}
		}
		
		
		rep(i,n){
			int a,b,c,d;
			cin>>a>>b>>c>>d;
			
			dp[a][b][0] = c;
			dp[b][a][0] = c;
			
			dp[a][b][1] = d;
			dp[b][a][1] = d;
		}
		
		for(int p=0;p<2;p++){
		for(int k=1;k<=m;k++){
			for(int i=1;i<=m;i++){
				for(int j=1;j<=m;j++){
					dp[i][j][p] = min(dp[i][j][p], dp[i][k][p]+dp[k][j][p]);
				}
			}
		}
		}
		
		int r;
		cin>>r;
		
		rep(i,r){
			int a,b,c;
			cin>>a>>b>>c;
			printf("%d\n",dp[a][b][c]);
		}
	}
}

C++: #include <iostream>
#include <algorithm>
#define INF 1000000000
using namespace std;
int cost[101][101];
int t_cost[101][101];
int main(){
  int n,m;
  while(cin >> n >> m , n+m ){
    m++;
    for(int i = 0  ; i < m ; i++ ){
      for(int j = 0  ; j < m ; j++ ){
	if(i == j)cost[i][j] = 0;
	else cost[i][j] = INF; 
	if(i == j)t_cost[i][j] = 0;
	else t_cost[i][j] = INF; 
      }
    }
    for(int i = 0 ; i < n ; i++ ){
      int a,b,c,d;
      cin >> a >> b >> c >> d;
      cost[a][b] = cost[b][a] = c;
      t_cost[a][b] = t_cost[b][a] = d;  
    }
    for(int i = 0 ; i < m ; i++ ){
      for(int j = 0 ; j < m ; j++ ){
	for(int k = 0 ; k < m ; k++ ){
	  cost[i][j] = min(cost[i][j],cost[i][k] + cost[k][j]);
	  t_cost[i][j] = min(t_cost[i][j],t_cost[i][k] + t_cost[k][j]);
	}
      }
    }
    int k;
    cin >> k;
    for(int i = 0 ; i < k ; i++ ){
      int from,to,r;
      cin >> from >> to >> r; 
      if(r == 0){
	cout << cost[from][to] << endl;
      } else {
	cout << t_cost[from][to] << endl;
      }
    }
  }
  return 0;
}