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]
					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 <algorithm>
#include <queue>
#include <functional>
#include <utility>
using namespace std;

typedef pair<int,int> P;

#define REP(i,b,n) for(int i=b;i<n;i++)
#define rep(i,n) REP(i,0,n)
#define mp make_pair
#define pb push_back

struct edge {
  int to, cost, time;
  edge(int a, int b, int c): to(a), cost(b), time(c) {}
};

const int MAX_M = 100, INF = 10000000;
int n, m;

void solve() {
  vector<edge> E[MAX_M+1];
  rep(i,n) {
    int a, b, cost, time; cin>>a>>b>>cost>>time;
    E[a].push_back(edge(b, cost, time));
    E[b].push_back(edge(a, cost, time));
  }
  int kkk; cin>>kkk;
  rep(i,kkk) {
    int p, q, r; cin>>p>>q>>r;
    // dijkstra
    int d[MAX_M+1];
    fill(d, d+MAX_M, INF);
    priority_queue<P, vector<P>, greater<P> > que;
    que.push(P(0, p));
    d[p] = 0;
    while (!que.empty()) {
      P p = que.top(); que.pop();
      int td = p.first, ti = p.second;
      //cout<<td<<"|"<<ti<<endl;
      if (d[ti] < td) continue;
      //
      rep(i,E[ti].size()) {
        edge e = E[ti][i];
        if (r == 0) {
          if (d[e.to] > d[ti] + e.cost) {
            d[e.to] = d[ti] + e.cost;
            que.push(P(d[e.to], e.to));
          }
        } else {
          if (d[e.to] > d[ti] + e.time) {
            d[e.to] = d[ti] + e.time;
            que.push(P(d[e.to], e.to));
          }
        }
      }
    }
    
    cout<<d[q]<<endl;
  }
}

int main (int argc, char const* argv[]) {
  while (cin>>n>>m, n||m) {
    solve();
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <map>
#define INF (int)1e9


void dijkstra(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > &v); 

int main(void) {
    int n;
    int m;
    int a;
    int b;
    int cost;
    int time;
    int k;
    int p;
    int q;
    int r;

    while (true) {
        std::cin >> n >> m;
        if (n == 0 && m == 0) {
            break; 
        }
        std::vector<std::vector<std::pair<int, int> > > vcost(m);
        std::vector<std::vector<std::pair<int, int> > > vtime(m);
        for (int i = 0; i < n; i++) {
            std::cin >> a >> b >> cost >> time;
            --a;
            --b;
            vcost[a].push_back(std::make_pair(cost, b));
            vcost[b].push_back(std::make_pair(cost, a));
            vtime[a].push_back(std::make_pair(time, b));
            vtime[b].push_back(std::make_pair(time, a));
        }
        std::cin >> k;
        for (int i = 0; i < k; i++) {
            std::cin >> p >> q >> r;
            --p;
            --q;
            if (r == 0) {
                dijkstra(m, p, q, vcost);
            } else {
                dijkstra(m, p, q, vtime);
            }
        }
    } return 0;
}

void dijkstra(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > &v) {
    std::vector<int> rvec(m, INF);
    rvec[p] = 0;
    std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int> >, std::greater<std::pair<int, int> > > pq;
    std::vector<int> search_count(m, 0);
    int start_value;
    int start_target;
    int end_value;
    int end_target;
    pq.push(std::make_pair(rvec[p], p));

    while(! pq.empty()) {
        start_target = pq.top().second;
        start_value = pq.top().first; 
        pq.pop();
        if (search_count[start_target] != 0) {
            continue;
        }
        ++search_count[start_target];
        for (int i = 0; i < v[start_target].size(); i++) {
            end_value = v[start_target][i].first;
            end_target = v[start_target][i].second;
            if (rvec[end_target] > end_value + rvec[start_target]) {
                rvec[end_target] = end_value + rvec[start_target];
                pq.push(std::make_pair(rvec[end_target], end_target));
            }
        }
    }
    std::cout << rvec[q] << std::endl;
    return;
}

C++: #include<iostream>
using namespace std;
int MAX=100000;
int main(){
  int n,m;
  cin>>n>>m;
  int a,b,cost,timer;
  int costs[m][m];
  int timers[m][m];
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      costs[i][j]=MAX;
      timers[i][j]=MAX;
    }
    costs[i][i]=0;
    timers[i][i]=0;
  }

  for(int i=0;i<n;i++){
    cin>>a>>b>>cost>>timer;
    costs[a-1][b-1]=cost;
    timers[a-1][b-1]=timer;
    costs[b-1][a-1]=cost;
    timers[b-1][a-1]=timer;
  }
  /*
  cout<<endl<<endl<<endl;
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      cout<<costs[i][j]<<"            ";
    }
    cout<<endl;
  }
  cout<<endl<<endl<<endl<<endl<<endl;*/
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      for(int k=0;k<m;k++){
        if(costs[j][k]>(costs[j][i]+costs[i][k])){
          costs[j][k]=costs[j][i]+costs[i][k];
          costs[k][j]=costs[j][i]+costs[i][k];
        }
        if(timers[j][k]>(timers[j][i]+timers[i][k])){
          timers[j][k]=timers[j][i]+timers[i][k];
          timers[k][j]=timers[j][i]+timers[i][k];
        }
      }
    }
  }
  int k;
  int p;
  int q;
  bool r;
  cin>>k;
  for(int i=0;i<k;i++){
    cin>>p>>q>>r;
    if(r){
      cout<<timers[p-1][q-1]<<endl;
    }else if(!r){
      cout<<costs[p-1][q-1]<<endl;
    }
  }
  return 0;
}