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
			c_matrix[b-1][a-1] = c
			t_matrix[a-1][b-1] = t
			t_matrix[b-1][a-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<vector>
#include<map>
#include<queue>
#include<functional>
#define INF 1000000000//INF=∞
using namespace std;
typedef pair<int, int> P;//firstは最短距離,secondは頂点番号

const int MAX_M = 100;

struct edge {
  int to, cost;
  //edge() : to(0), cost(0) {}
  //edge(int to, int cost) : to(to), cost(cost) {}
};
int V;//頂点の数

vector<vector<edge> > time_graph(MAX_M); //頂点間の距離情報(隣接リスト)
vector<vector<edge> > cost_graph(MAX_M);

vector<vector<int> > time_ds(MAX_M);
vector<vector<int> > cost_ds(MAX_M);

int dijkstra(vector<vector<edge> >& G, vector<vector<int> >& ds, int s, int g){
  if (!ds[s].empty()) return ds[s][g];
  
  priority_queue<P, vector<P>, greater<P> > que;
  vector<int> d(V, INF);//最短距離を記録する配列(∞で初期化しておく)
  d[s] = 0;//頂点sから頂点sへの最短距離は0で確定
  que.push(P(0, s));//距離0,頂点sからスタート

  while(!que.empty()){
    /*処理1*/
    //キューの中で最も頂点sからの距離が近い頂点vとその距離cを取得
    P p = que.top();
    que.pop();
    int v = p.second, c = p.first;

    /*処理2*/
    //頂点vの最短距離がすでに確定していたらcontenue
    if(d[v] < c)
      continue;

    /*処理3*/
    //頂点vの最短距離が既に確定していなければ頂点vへの最短経路はcで確定
      d[v]=c;

    /*処理4*/
    //頂点vから移動しうる頂点とその距離をキューに入れる
    for(int i = 0; i < G[v].size(); i++){
      //頂点vはG[v].size()個の行き先を持つ
      edge e = G[v][i];
      if(d[e.to] > d[v] + e.cost){
        que.push(P(d[v] + e.cost, e.to));
      }
    }
  }
  ds[s] = d;
  return d[g];//頂点gへの最短距離を返す
}

int main() {
  int n, m;
  while (cin >> n >> m, n || m) {
    V = m;

    for (int i = 0; i < MAX_M; i++) {
      time_graph[i].clear();
      time_ds[i].clear();
      cost_graph[i].clear();
      cost_ds[i].clear();
    }

    for (int i = 0; i < n; i++) {
      int a, b, time, cost;
      cin >> a >> b >> time >> cost;
      a--; b--; // 0-indexedにする
      edge e1,e2,e3,e4;
      e1.to = e3.to = b; e1.cost = e2.cost = time;
      e2.to = e4.to = a; e3.cost = e4.cost = cost;
      time_graph[a].push_back(e1);
      time_graph[b].push_back(e2);
      cost_graph[a].push_back(e3);
      cost_graph[b].push_back(e4);
    }

    int k;
    cin >> k;
    for (int i = 0; i < k; i++) {
      int p, q, r;
      cin >> p >> q >> r;
      p--; q--;
      if (p > q) swap(p, q);
      if (r == 0)
        cout << dijkstra(time_graph, time_ds, p, q) << endl;
      else
        cout << dijkstra(cost_graph, cost_ds, p, q) << endl;
    }
  }
}

C++: #include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;

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

//4方向ベクトル→↑←↓
int dx[] ={1,0,-1,0};
int dy[] ={0,-1,0,1};

int n,m;//線路の情報の数,駅の数
int dpc[101][101];
int dpt[101][101];
const int INF = 100000000;


void WarshallFloyd(){
  for(int i = 1;i <= m;i++){
    for(int j = 1;j <=m;j++){
      for(int k = 1;k <=m;k++){
      dpc[j][k] =min(dpc[j][k],dpc[j][i]+dpc[i][k]);
      dpt[j][k] =min(dpt[j][k],dpt[j][i]+dpt[i][k]);
      }
    }
  }
  return;
}

int main()
{
  while(cin >>n>>m){
    if(n ==0&&m ==0){
      break;
    }
   
    for(int i = 1;i <=m ;i++){
      for(int j = i+1;j <=m;j++){
	dpc[i][j] =INF;
	dpc[j][i] =INF;
	dpt[i][j] =INF;
	dpt[j][i] =INF;
      }
    }
    for(int i = 1;i <= m;i++){
      dpc[i][i] = 0;
      dpt[i][i] = 0;
    }
    for(int i = 0;i < n;i++){
      int from,to,cost,time;
      cin >>from>>to>>cost>>time;
      dpc[from][to] =cost;
      dpt[from][to] =time;
      dpc[to][from] =cost;
      dpt[to][from] =time;
    }
    /* for(int i = 1;i <=m;i++){
      for(int j = 1;j <=m;j++){
	cout <<"dpc["<<i<<"]["<<j<<"]"<<dpc[i][j] <<endl;
	cout <<"dpt["<<i<<"]["<<j<<"]"<<dpt[i][j] <<endl;
      }
      }*/
    WarshallFloyd();
    int k;//問い合わせの数
    cin >>k;
    for(int i = 0;i <k;i++){
      int s;
      int f;
      int r;
      cin >>s>>f>>r;
      if(r)
	cout<<dpt[s][f]<<endl;
      else
	cout<<dpc[s][f]<<endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;

const int MAX=1001;
const int INF=(1<<21);

int main(){

  int n,m;
  int a,b,cost,time;
  int p,q,r;
  int rail_cost[MAX][MAX];
  int rail_time[MAX][MAX];

  while(1){
    cin>> n>> m;
    if(n==0 && m==0) break;
  
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      rail_cost[i][j]=INF;
      rail_time[i][j]=INF;
    }
  }

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

  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      for(int k=0;k<m;k++){
	rail_cost[j][k]=min(rail_cost[j][k],rail_cost[j][i]+rail_cost[i][k]);
	rail_time[j][k]=min(rail_time[j][k],rail_time[j][i]+rail_time[i][k]);
      }
    }
  }

  cin>> n;
  for(int i=0;i<n;i++){
    cin>> p>> q>> r;
    if(r==0){
      cout<< rail_cost[p-1][q-1]<< endl;
    }else{
      cout<< rail_time[p-1][q-1]<< endl;
    }
  }

  }
}