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>
using namespace std;

struct Node{
  int num;

  vector<int> edge_to;
  vector<int> edge_cost;
  vector<int> edge_time;

  bool done;
  int cost;
  int time;
};

int main(){
  for(;;){
    int n,m,a,b,c,t,p,q,r;
    cin>>n>>m;
    if(n==0&&m==0)break;
    vector<Node> node;

    Node no;

    for(int i=1;i<=m;i++){
      no.num=i;
      no.done=false;
      no.cost=-1;
      no.time=-1;
      node.push_back(no);
    }


    while(n--){
      cin>>a>>b>>c>>t;
      node[a-1].edge_to.push_back(b);
      node[b-1].edge_to.push_back(a);
      node[a-1].edge_cost.push_back(c);
      node[b-1].edge_cost.push_back(c);
      node[a-1].edge_time.push_back(t);
      node[b-1].edge_time.push_back(t);
    }

    cin>>n;
    while(n--){
      cin>>p>>q>>r;

      vector<Node> n(node.size());
      copy(node.begin(),node.end(),n.begin());
      p--;
      q--;

      if(r){

	n[p].time = 0;
	while(1){

	  int d=-1;

	  for(int i=0;i<n.size();++i){
	    if( n[i].done || n[i].time < 0) {
	      continue;
	    } else if(d == -1 || n[i].time < n[d].time) {
	      d=i;
	    }
	  }

	  if ( d == -1 )
	    break;

	  n[d].done = true;

	  for(int i=0;i<n[d].edge_to.size();++i) {
	    int ttime = n[d].time + n[d].edge_time[i];
	    if(n[n[d].edge_to[i]-1].time < 0 || ttime < n[n[d].edge_to[i]-1].time){
	      n[n[d].edge_to[i]-1].time = ttime;
	    }
	  }

	}
	cout<<n[q].time<<endl;

      }else{

	n[p].cost = 0;
	while(1){

	  int d=-1;

	  for(int i=0;i<n.size();++i){
	    if( n[i].done || n[i].cost < 0) {
	      continue;
	    } else if(d == -1 || n[i].cost < n[d].cost ) {
	      d=i;
	    }
	  }

	  if ( d == -1 )
	    break;

	  n[d].done = true;

	  for(int i=0;i<n[d].edge_to.size();++i) {
	    int tcost= n[d].cost + n[d].edge_cost[i];
	    if(n[n[d].edge_to[i]-1].cost < 0 || tcost < n[n[d].edge_to[i]-1].cost){
	      n[n[d].edge_to[i]-1].cost = tcost;
	    }
	  }

	}
	cout<<n[q].cost<<endl;

      }

    }
  }
}

C++: #include<iostream>
using namespace std;
int main(){
  const int MAX = 1e5;
  for(int n,m;cin>>n>>m,n;){
    int cost[m][m];
    int time[m][m];
    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
	cost[i][j] = MAX;
	time[i][j] = MAX;
      }
    }
    int a,b,c,t;
    for(int i=0;i<n;i++){
      cin>>a>>b>>c>>t;
      cost[a-1][b-1] = c;
      cost[b-1][a-1] = c;
      time[a-1][b-1] = t;
      time[b-1][a-1] = t;
    }
    for(int k=0;k<m;k++){
      for(int i=0;i<m;i++){
	for(int j=0;j<m;j++){
	  if(cost[i][j]>cost[i][k]+cost[k][j])
	    cost[i][j] = cost[i][k]+cost[k][j];
	  if(time[i][j]>time[i][k]+time[k][j])
	    time[i][j] = time[i][k]+time[k][j];
	}
      }
    }
    int l,r;
    cin>>l;
    for(int i=0;i<l;i++){
      cin>>a>>b>>r;
      if(r)
	cout<<time[a-1][b-1]<<endl;
      else
	cout<<cost[a-1][b-1]<<endl;      
    }
  }
  return 0;
}

C++: #include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <functional>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>
using namespace std;
inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string toString(T x) { ostringstream sout; sout << x; return sout.str();}
typedef vector<int> vi;
typedef vector<vi>  vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EACH(t,i,c) for(t::iretator i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define REP(i,n) FOR(i,0,(n)-1)
const double EPS = 1e-10;
const double PI = acos(-1.0);

const int INF = INT_MAX/10;

struct state {
	int s, c;
	state(int s, int c) : s(s), c(c) {};
	bool operator<(const state other)const {
		return c>other.c;
	}
};

int main() {
	int n, m;
	while(cin >> n >> m, n) {
		int a, b, c, t;
		vector<vvi> data(2, vvi(m, vi(m, INF)));
		REP(i, n) {
			cin >> a >> b >> c >> t;
			data[0][a-1][b-1] = c;
			data[0][b-1][a-1] = c;
			data[1][a-1][b-1] = t;
			data[1][b-1][a-1] = t;
		}
		
		int k;
		cin >> k;
		REP(i, k) {
			int p, q, r;
			cin >> p >> q >> r;

			priority_queue<state> Q;
			Q.push(state(p-1, 0));
			vi cost(n, INF);
			cost[p-1] = 0;
			while(!Q.empty()) {
				state st = Q.top();
				Q.pop();
				if(st.s == q-1) {
					cost[q-1] = min(cost[q-1], st.c);
					continue;
				}
				REP(j, m) {
					if(st.s != j && data[r][st.s][j] != INF) {
						int ncost = st.c + data[r][st.s][j];
						if(ncost < cost[j]) {
							cost[j] = ncost;
							Q.push(state(j, ncost));
						}
					}
				}
			}
			cout << cost[q-1] << endl;
		}
	}

	return 0;
}