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++: //青春の片道切符：：ワーシャルフロイド法

	/*for(int k=0;k<N;k++){//経由箇所(N<200)
		for(int i=0;i<N;i++){//スタート(N<200)
			for(int j=0;j<N;j++){//目的(N<200)
				d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
			}
		}
	}*/


#include<iostream>
#include<string>
#include<queue>
#include<utility>
#include<algorithm>
#include<cctype>
using namespace std;

long long gc[110][110];
long long gt[110][110];
int n,m;

void warshallfroid(){
	for(int k=0;k<n;k++){//経由箇所(N<200)
		for(int i=0;i<n;i++){//スタート(N<200)
			for(int j=0;j<n;j++){//目的(N<200)
				gc[i][j]=min(gc[i][j],gc[i][k]+gc[k][j]);
				gt[i][j]=min(gt[i][j],gt[i][k]+gt[k][j]);
			}
		}
	}
}



int main(){
	
	while(cin>>n>>m,n||m/*n,mが両方0のときお終わり*/){
		for(int i=0;i<n;i++){//スタート(N<200)
			for(int j=0;j<n;j++){//目的(N<200)
				gc[i][j]=9999999;//初期化
				gt[i][j]=9999999;//初期化
			}
		}
	

	
	for(int i=0;i<n;i++){
		int a,b,c,t;
		cin>>a>>b>>c>>t;
		a--,b--;
		gc[a][b]=gc[b][a]=c;
		gt[a][b]=gt[b][a]=t;
	}
	warshallfroid();
	
	int k;
	cin>>k;
	for(int i=0;i<k;i++){
	int p,q,r;
		cin>>p>>q>>r;
		p--,q--;
		if(r==0)cout<<gc[p][q]<<endl;
		else cout<<gt[p][q]<<endl;
	}
	
	}

}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define N 100
#define M 10000

using namespace std;

int Dijkstra(vector< vector<int> > data, int s, int g){
  vector<bool> is_reached(data.size(), false);
  vector<int> ans(data.size(), M);
  ans[s] = 0;

  int i, j;
  i = s;
  while(i != g){
    is_reached[i] = true;
    for(j=0; j<data[i].size(); ++j){
      ans[j] = min(ans[j], ans[i] + data[i][j]);
    }
    for(i=-1, j=0; j<is_reached.size(); ++j){
      if(!is_reached[j] && (i < 0 || ans[i] > ans[j])) i = j;
    }
  }
  return ans[g];
}

int main(){
  int n, m, a, b, c, t;
  int p, q, r;

  while(1){
    cin >> n >> m;
    if(n == 0 && m == 0) break;
    vector< vector<int> > cost(m, vector<int>(m, M));
    vector< vector<int> > time(m, vector<int>(m, M));

    for(int i=0; i<n; ++i){
      cin >> a >> b >> c >> t;
      --a;
      --b;
      cost[a][b] = c;
      cost[b][a] = c;
      time[a][b] = t;
      time[b][a] = t;
    }
    cin >> n;
    for(int i=0; i<n; ++i){
      cin >> p >> q >> r;
      --p;
      --q;
      if(r == 0) cout << Dijkstra(cost, p, q) << endl;
      else cout << Dijkstra(time, p, q) << endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <queue>
#include <vector>
#include <string>
#include <map>
#include <algorithm>

#define REP(i,n) for(int i=0;i<(int)(n);i++)

using namespace std;

int dijkstra(const vector<vector<int>>& to, const vector<vector<int>>& w, int s, int t, int n) {
  vector<int> weight(n, 1000000000);
  weight[s] = 0;
  priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> q;
  q.push(make_pair(0,s));
  while(!q.empty()){
    auto p = q.top(); q.pop();
    if(p.first > weight[p.second]) continue;
    for(int i = 0;i < to[p.second].size(); ++i) {
      if (weight[to[p.second][i]] > p.first + w[p.second][i]) {
        weight[to[p.second][i]] = p.first + w[p.second][i];
        q.push(make_pair(weight[to[p.second][i]], to[p.second][i]));
      }
    }
  }
  return weight[t];
}


int main() {
  while(1){
    int n,m;
    cin>>n>>m;
    if(!n) break;
    vector<vector<int>> to(m);
    vector<vector<int>> cost(m);
    vector<vector<int>> time(m);
    for (int i = 0; i < n; ++i) {
      int a, b, c, t;
      cin >> a >> b >> c >> t;
      --a;--b;
      to[a].push_back(b);
      to[b].push_back(a);
      cost[a].push_back(c);
      cost[b].push_back(c);
      time[a].push_back(t);
      time[b].push_back(t);
    }
    int k;
    cin >> k;
    for (int i = 0; i < k; ++i) {
      int p,q,r;
      cin >> p >> q >> r;
      --p;--q;
      if (r == 0) {
        cout << dijkstra(to,cost,p,q, m) << endl;
      } else {
        cout << dijkstra(to,time,p,q, m) << endl;
      }
    }
  }
  return 0;
}

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

using namespace std;

#define loop(i,a,b) for(int i=(a); i<(int)(b); i++)
#define rep(i,b) loop(i,0,b)


struct edge {
    int from,to,money,time;
};
int d[101];
vector<edge> E;

int main(){
    int n,m;
    while(cin>>n>>m, n|m){
        E.resize(n);
        for(edge& e:E){
            cin>>e.from>>e.to>>e.money>>e.time;
        }
        int k; cin>>k;
        rep(i,k){
            int a,b,c; cin>>a>>b>>c;
            for(int& x:d) x=1<<30;
            d[a]=0;
            while(1){
                bool end=true;
                for(edge& e:E){
                    rep(dir,2){
                        int cost=(c==0 ? e.money : e.time);
                        if(d[e.to]>d[e.from]+cost){
                            d[e.to]=d[e.from]+cost;
                            end=false;
                        }
                        swap(e.from,e.to);
                    }
                }
                if(end) break;
            }
            cout<<d[b]<<endl;
        }
    }
}