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 <algorithm>
#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;

template <typename T>
struct Edge { int src, dst; T cost;
    Edge(int dst, T cost) : src(-1), dst(dst), cost(cost) { }
    Edge(int src, int dst, T cost) : src(src), dst(dst), cost(cost) { }
};
template <typename T> using Edges = vector<Edge<T>>;
template <typename T> using WeightedGraph = vector<Edges<T>>;
template <typename T> using Matrix = vector<vector<T>>;

template <typename T>
void warshall_floyd(Matrix<T> &g) {
    const T INF = numeric_limits<T>::max();
    for (int k = 0; k < g.size(); k++) {
        for (int i = 0; i < g.size(); i++) if (g[i][k] != INF) {
            for (int j = 0; j < g.size(); j++) if (g[k][j] != INF) {
                g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
            }
        }
    }
}

int main() {
    int n, m;
    const auto INF = numeric_limits<int>::max();
    while (cin >> n >> m, n) {
        Matrix<int> cost(m, vector<int>(m, INF));
        Matrix<int> time(m, vector<int>(m, INF));
        for (int i = 0; i < m; i++) cost[i][i] = 0, time[i][i] = 0;
        while (n--) {
            int a, b, c, t; cin >> a >> b >> c >> t; a--, b--;
            cost[a][b] = cost[b][a] = c;
            time[a][b] = time[b][a] = t;
        }
        warshall_floyd(cost);
        warshall_floyd(time);
        int k; cin >> k;
        while (k--) {
            int p, q, r; cin >> p >> q >> r; p--, q--;
            cout << (r == 0 ? cost[p][q] : time[p][q]) << endl;
        }
    }
    return 0;
}

C++: //AOJ 0200
//菴ソ縺?婿繧ゅｏ縺九ｉ縺ェ縺?¥縺帙↓include縺励∪縺上ｋ莠コ髢薙?繧ッ繧コ
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<stack>
#include<queue>
#include<vector>
#include<list>
#include<deque>
using namespace std;
#define INF 1 << 20
#define MAX_B 101

int a, b, i, j, k, money[MAX_B][MAX_B], time[MAX_B][MAX_B], n, m, c, d;
bool judge;
stack<int> left, right;


int main(){
  while(1){
    scanf("%d %d", &n, &m);
    if(n == 0 && m == 0) return 0;
    for(i = 1; i <= m; i++){
      for(j = 1; j <= m; j++){
	money[i][j] = INF;
	time[i][j] = INF;
      }
    }
    for(i = 1; i <= m; i++){
      money[i][i] = 0;
      time[i][i] = 0;
    }
    for(i = 0; i < n; i++){
      scanf("%d %d %d %d", &a, &b, &c, &d);
      money[a][b] = c;
      money[b][a] = c;
      time[a][b] = d;
      time[b][a] = d;
    }
    scanf("%d", &a);
    for(i = 1; i <= m; i++){
      for(j = 1; j <= m; j++){
	for(k = 1; k <= m; k++){
	  if(money[j][k] > money[j][i] + money[i][k]){
	    money[j][k] = money[j][i] + money[i][k];
	    money[k][j] = money[j][i] + money[i][k];
	  }
	  if(time[j][k] > time[j][i] + time[i][k]){
	    time[j][k] = time[j][i] + time[i][k];
	    time[k][j] = time[j][i] + time[i][k];
	  }
	}
      }
    }
    for(i = 0; i < a; i++){
      scanf("%d %d %d", &b, &c, &d);
      if(d == 1)
	printf("%d\n", time[b][c]);
      if(d == 0)
	printf("%d\n", money[b][c]);
    }
  }
  return 0;
}

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

const int INF = 1<<27;
using namespace std;
typedef pair<int,int> P;
string IntToString(int);
int StringToInt(string);
struct edje{
public:
  int from;
  int to;
  int cost;
  edje(int f,int t,int c){
    from = f;
    to = t;
    cost = c;
  }
};

void bellmanFord(vector<int> &map,vector<edje> &cost){
  for(int i = 0;i < map.size()-1;i++){
    for(int j = 0;j < cost.size();j++){
      map[cost[j].to] = min(map[cost[j].to],map[cost[j].from] + cost[j].cost);
    }
  }
}
void dijkstra(int s,vector<vector<P> >& cost,vector<int>& map){
  map[s] = 0;
  
  priority_queue<P,vector<P>,greater<P> > que;
  que.push(P(0,s));
  while(!que.empty()){
    P p = que.top();
    que.pop();
    int v = p.second;
    if(map[v] < p.first)continue;//
    for(int i = 0;i < cost[v].size();i++){
      if(map[cost[v][i].first] > map[v] + cost[v][i].second){
	map[cost[v][i].first] = map[v] + cost[v][i].second;
	que.push(P(map[cost[v][i].first],cost[v][i].first));
      }
    }

  }
}
int main(){
  while(1){
    int n,m;
    cin >> n >> m;
    if(n == 0 && m == 0)break;
    vector<vector<pair<int,int> > > cost(m);
    vector<vector<pair<int,int> > > time(m);
    for(int i = 0;i < n;i++){
      int a,b,c,t;
      cin >> a >> b >> c >> t;
      cost[a-1].push_back(pair<int,int>(b-1,c));
      cost[b-1].push_back(pair<int,int>(a-1,c));
      time[a-1].push_back(pair<int,int>(b-1,t));
      time[b-1].push_back(pair<int,int>(a-1,t));
    }
    int k;
    cin >> k;
    for(int i = 0;i < k;i++){
      int s,g,q;
      cin >> s >> g >> q;
      vector<vector<pair<int,int> > > tmp;
      if(q == 0) tmp = vector<vector<pair<int,int> > >(cost);
      else if(q == 1) tmp = vector<vector<pair<int,int> > >(time);
      vector<int> map(m,INF);
      //      map[s-1] = 0;
      dijkstra(s-1,tmp,map);
      cout << map[g-1] << endl;
      

    }
  }
  return 0;   
}
string IntToString(int number){
  stringstream ss;
  ss << number;
  return ss.str();
}
int StringToInt(string number){
  stringstream ss;
  ss << number;
  int numInt;
  ss >> numInt;
  return numInt;
  
}