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<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#include<set>
#include<complex>
#include<map>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<s;i++)
#define CC puts("-------ok--------");
#define all(in) in.begin(), in.end()
using namespace std;
typedef pair<int,int> pii;
#define MAX 99999999
signed main(){
while(1){
	int n,m;
	cin>>n>>m;
    if(!(n+m))break;
	vector<vector<pii>>v(m+1,vector<pii>(m+1,pii(INF,INF)));
	rep(i,n+1)v[i][i]=pii(0,0);
	rep(i,n){
		pii temp;
		int s,g;
		cin>>s>>g>>temp.first>>temp.second;
        v[--s][--g]=temp;
	}
    n=m;
    rep(k,n){
        rep(i,n){
            rep(j,n){
                v[i][j].first=min(v[i][k].first+v[k][j].first,v[i][j].first);
                v[i][j].second=min(v[i][k].second+v[k][j].second,v[i][j].second);

            }
        }
    }
    int k; cin>>k;
    rep(i,k){
        int s,g,r; cin>>s>>g>>r;
        if(!r)cout<<v[--s][--g].first<<endl;
        else cout<<v[--s][--g].second<<endl;
    }
    
    }
}

C++: #include <bits/stdc++.h>
using namespace std;

#define ll long long
#define vvi vector< vector<int> >
#define vi vector<int>
#define All(X) X.begin(),X.end()
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define pb push_back
#define pii pair<int,int>
#define mp make_pair
#define pi 3.14159265359
#define shosu(X) fixed << setprecision(X)
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
const ll int INF = 1e9;
int ti[101][101];//time
int co[101][101];//cost
int n,m;
int main(){
	while(1){
		cin >> n >> m; 
		if(n == 0 && m == 0) break;
		REP(i,101) REP(j,101) ti[i][j] = co[i][j] = INF;
		REP(i,101) ti[i][i] = co[i][i] = 0;

		REP(i,n){
			ll int a,b,cost,tim;
			cin >> a >> b >> cost >> tim;
			a--; b--;
			co[a][b] = co[b][a] = cost;
			ti[a][b] = ti[b][a] = tim;
		}
		//Warshall???Floyd Algorithm
		REP(k,m){
			REP(i,m){
				REP(j,m){
					ti[i][j] = min(ti[i][j], ti[i][k] + ti[k][j]);
					co[i][j] = min(co[i][j], co[i][k] + co[k][j]);
				}
			}
		}
		int k;
		cin >> k;
		REP(i,k){
			int a,b,r;
			cin >> a >> b >> r;
			a--; b--;
			if(r == 0) cout << co[a][b] << endl;
			else cout << ti[a][b] << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <complex>
#include <cstring>
#include <cstdlib>
#include <string>
#include <cmath>
#include <queue>
using namespace std;

#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
const int INF = 1<<30;


typedef int Weight;
struct Edge {
  int src, dst;
  Weight weight;
  Edge(int src, int dst, Weight weight) :
    src(src), dst(dst), weight(weight) { }
};

bool operator < (const Edge &e, const Edge &f) {
  return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!!
    e.src != f.src ? e.src < f.src : e.dst < f.dst;
}

typedef vector<Edge> Edges;
typedef vector<Edges> Graph;


// ¹öª¢çÈ¢ê
vector<Weight> dijkstra2(const Graph &g, int s) {
  int n = g.size();
  vector<Weight> dist(n, INF);
  dist[s] = 0;
  priority_queue<Edge> Q; // "e < f" <=> "e.weight > f.weight"
  for (Q.push(Edge(-2, s, 0)); !Q.empty(); ) {
    Edge e = Q.top(); Q.pop();
    if (dist[e.dst] < e.weight) continue;
    FOR(f,g[e.dst]) {
      if (dist[f->dst] > e.weight+f->weight) {
        dist[f->dst] = e.weight+f->weight;
        Q.push(Edge(f->src, f->dst, e.weight+f->weight));
      }
    }
  }
  return dist;
}

int main() {
  int n, m;
  while(cin>>n>>m,n||m) {
    Graph g1(m), g2(m);
    REP(i,n) {
      int a, b, cost, time;
      cin >> a>> b >> cost >> time;
      a--;b--;
      g1[a].push_back(Edge(a,b,cost));
      g1[b].push_back(Edge(b,a,cost));
      g2[a].push_back(Edge(a,b,time));
      g2[b].push_back(Edge(b,a,time));
    }
    int k;
    cin >> k;
    REP(i,k) {
      int p,q,r;
      cin >> p >> q >> r;
      p--;q--;
      vector<Weight> dist;
      if (r == 0) {
        dist = dijkstra2(g1, p);
      } else {
        dist = dijkstra2(g2, p);
      }
      cout << dist[q] << endl;
    }
  }
}