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()
{
  cin >> 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(i, V) dp[0][i][i] = dp[1][i][i] = 0LL;
  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 <iostream>
#include <algorithm>
#include <utility>
#include <vector>

const int INF = 10000000;

using Mat = std::vector< std::vector<int> >;

void wf(Mat& adj_mat) {
  int n = adj_mat.size();

  for(int i = 0; i < n; ++i) {     // via node
    for(int j = 0; j < n; ++j) {   // start
      for(int k = 0; k < n; ++k) { // terminal
        adj_mat[j][k] = std::min(adj_mat[j][k], adj_mat[j][i] + adj_mat[i][k]);
      }
    }
  }
}

int main() {
  while(1){
    int n, m;
    int a, b, cost, time;

    std::cin >> n >> m;
    if (n == 0)
      break;

    Mat cost_table, time_table;
    cost_table.resize(m);
    time_table.resize(m);
    for(int i = 0; i < m; ++i) {
      cost_table.at(i).resize(m);
      time_table.at(i).resize(m);
      for(int j = 0; j < m; ++j){
        cost_table[i][j] = INF;
        time_table[i][j] = INF;
      }
    }

    for(int i = 0; i < n; ++i){
      std::cin >> a >> b >> cost >> time;
      --a, --b;
      cost_table[a][b] = cost_table[b][a] = cost;
      time_table[a][b] = time_table[b][a] = time;
    }

    wf(cost_table);
    wf(time_table);

    // Query
    int k;
    int p, q, r;
    std::cin >> k;
    for(int i = 0; i < k; ++i){
      std::cin >> p >> q >> r;
      --p, --q;
      if (r == 0)
        std::cout << cost_table[p][q] << std::endl;
      else
        std::cout << time_table[p][q] << std::endl;
    }
  }
}

C++: #include <iostream>
#include <set>
#include <vector>
#include <string>
#include <utility>
#include <algorithm>
using namespace std;
typedef pair<int,int> P;
int n,m,K;
int cost[100][100],tim[100][100];
int main()
{
    while(cin>>n>>m&&(n||m)){
		fill(cost[0],cost[100],1000000);
		fill(tim[0],tim[100],1000000);
		for(int i=0;i<n;i++){
			int a,b,c,t;cin>>a>>b>>c>>t;a--;b--;
			cost[a][b]=cost[b][a]=c;
			tim[a][b]=tim[b][a]=t;
		}
		for(int k=0;k<m;k++)
			for(int i=0;i<m;i++)
				for(int j=0;j<m;j++){
					cost[i][j]=min(cost[i][j],cost[i][k]+cost[k][j]);
					tim[i][j]=min(tim[i][j],tim[i][k]+tim[k][j]);
				}
		cin>>K;
		while(K--){
			int p,q,r;
			cin>>p>>q>>r;p--;q--;
			if(r==0)cout<<cost[p][q]<<endl;
			else cout<<tim[p][q]<<endl;
		}
	}
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
	int a, b, time, cost, querys;
	int i, j, k, p, q, r, n, m;
	int times[100][100], costs[100][100];

	while (true) {
		cin >> n >> m;
		if (!n && !m)
			break;

		for (i = 0; i < m; i++) {
			for (j = 0; j < m; j++) {
				times[i][j] = (i == j) ? 0 : 1e9;
				costs[i][j] = (i == j) ? 0 : 1e9;
			}
		}

		for (i = 0; i < n; i++) {
			cin >> a >> b >> cost >> time;
			times[a - 1][b - 1] = time;
			costs[a - 1][b - 1] = cost;
		}

		for (k = 0; k < m; k++) {
			for (i = 0; i < m; i++) {
				for (j = 0; j < m; j++) {
					times[i][j] = min(times[i][j], times[i][k] + times[k][j]);
					costs[i][j] = min(costs[i][j], costs[i][k] + costs[k][j]);
				}
			}
		}

		cin >> querys;
		for (i = 0; i < querys; i++) {
			cin >> p >> q >> r;
			cout << r ? times[p - 1][q - 1] : costs[p - 1][q - 1] << endl;
		}
	}
}