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<iostream>
#include<algorithm>
#include<climits>
using namespace std;
const int INF = INT_MAX/3;
const int MAXN = 2000;
const int TIME = 1,COST = 0;

int graph[2][MAXN][MAXN];

int n,m,a,b,c,t;

void solve();

void init(){
  for(int i = 0;i < m;i++)
    for(int j = 0;j < m;j++)
      graph[0][i][j] =graph[0][j][i] = graph[1][j][i] = graph[1][i][j] = INF;
}
int main(){
  cin >> n >> m;
  init();
  for(int i = 0;i < n;i++){
    cin >> a >> b >> c >> t;
    graph[TIME][a-1][b-1] = graph[TIME][b-1][a-1] = t;
    graph[COST][a-1][b-1] = graph[COST][b-1][a-1] = c;
  }
  solve();

  int X;
  cin >> X;
  for(int i = 0;i < X;i++){
    cin >> a >> b >> c;
    cout << graph[c][a-1][b-1] << endl;
  }
  return 0;
}

void solve(){
  for(int k = 0;k < m;k++){
    for(int i = 0;i < m;i++){
      for(int j = 0;j < m;j++){
	graph[0][i][j] = min(graph[0][i][j],graph[0][i][k] + graph[0][k][j]);
	graph[1][i][j] = min(graph[1][i][j],graph[1][i][k] + graph[1][k][j]);
      }
    }
  }
}

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){
  while(scanf(" %d %d", &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;
      scanf(" %d %d %d %d", &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;
    scanf(" %d", &k);
    while(k--){
      //      cin >> p >> q >> r;
      scanf(" %d %d %d", &p, &q, &r);
      //      cout << dp[r][p-1][q-1] << endl;
      printf("%lld\n", dp[r][p-1][q-1]);
    }
  }

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int main(void){

	int n, m, a, b, cost, time, k, p, q, r;
	int d_cost[101][101], d_time[101][101];

	while (cin >> n >> m && n != 0 && m != 0){

		for (int i = 1; i < m + 1; i++){
			for (int j = 1; j < m + 1; j++){

				d_cost[i][j] = 1001;
				d_time[i][j] = 1001;
			}
		}

		for (int i = 0; i < n; i++){

			cin >> a >> b >> cost >> time;
			d_cost[a][b] = cost;
			d_cost[b][a] = cost;
			d_time[a][b] = time;
			d_time[b][a] = time;
		}

		cout << endl;
		for (int i = 1; i < m; i++){
			for (int j = 1; j < m; j++){

				printf("%5d", d_cost[i][j]);
			}
			cout << endl;
		}
		cout << endl;
		for (int i = 1; i < m; i++){
			for (int j = 1; j < m; j++){

				printf("%5d", d_time[i][j]);
			}
			cout << endl;
		}

		for (int i = 1; i < m + 1; i++){
			for (int j = 1; j < m + 1; j++){
				for (int k = 1; k < m + 1; k++){

					d_cost[j][k] = min(d_cost[j][k], d_cost[j][i] + d_cost[i][k]);
					d_time[j][k] = min(d_time[j][k], d_time[j][i] + d_time[i][k]);
				}
			}
		}

		cin >> k;

		for (int i = 0; i < k; i++){

			cin >> p >> q >> r;

			if (r == 0)
				cout << d_cost[p][q] << endl;
			else
				cout << d_time[p][q] << endl;
		}
	}
}