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++: #include <iostream>
#include <vector>
#include <string.h>

using namespace std;

static const int TYPE_COST =0;
static const int TYPE_TIME =1;

class station{
public:
	int cost;
	bool visited;
	vector<int> edge_to;
	vector<int> edge_cost;
	vector<int> edge_time;
	
	 public:
		station() :  cost(-1), visited(false){}
		void add_to(int to, int cost, int time)
		{
			this->edge_to.push_back(to);
			this->edge_cost.push_back(cost);
			this->edge_time.push_back(time);
		}
};

int dijkstra(station* sta, int size, int from, int to, int type);
bool contain(vector<station> sta, station elem);
void reset(station* sta, int size);

int main(int argc, char** argv)
{
	while( 1 ){
		int n, m, from, to, cost, time, type;
		cin >> n;
		cin >> m;
		if(n==0 && m==0) break;
		
		station sta[m];
		for(int i=0; i<m; i++){
			sta[i] = station();
		}
		
		for(int i=0; i<n; i++){
			cin >> from;
			cin >> to;
			cin >> cost;
			cin >> time;
			sta[from-1].add_to(to-1, cost, time);
		}
		cin >> n;
		for(int i=0; i<n; i++){
			cin >> from;
			cin >> to;
			cin >> type;
			cout << dijkstra(sta, m, from-1, to-1, type) << endl;
			reset(sta, m);
		}
	}
	
	return 0;
}

int dijkstra(station* sta, int size, int start, int goal, int type)
{
	int to, cost;
	station done;
	vector<station> q;
	sta[start].cost = 0;
	q.push_back(sta[start]);
	
	while(!q.empty()){
		done = q[0];
		q.erase(q.begin());
		done.visited = true;
		
		for(int i=0; i<done.edge_to.size(); i++){
			if(!sta[to].visited){
				to = done.edge_to[i];
				if(type==TYPE_COST) cost = done.cost + done.edge_cost[i];
				if(type==TYPE_TIME) cost = done.cost + done.edge_time[i];
				if(sta[to].cost < 0 || cost < sta[to].cost){
					sta[to].cost = cost;
					if(!contain(q, sta[to])){
						q.push_back(sta[to]);
					}
				}
			}
		}	
	}
	
	return sta[goal].cost;
}

bool contain(vector<station> sta, station elem)
{
	int size = sta.size();
	bool is_match = false;
	for(int i=0; i<size; i++){
		if(memcmp(&sta[i], &elem, sizeof(station)) == 0){
			is_match = true;
			break;
		}
	}
	return is_match;
}

void reset(station* sta, int size)
{
	for(int i=0; i<size; i++){
		sta[i].visited = false;
		sta[i].cost = -1;
	}
}

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

const int INF = 2000;

struct LineTable{
  int cost;
  int times;
  LineTable(){
    cost = INF;
    times = INF;
  }
};

int main(){

    int n,m;
    while(1){
      cin >> n >> m;
      if(n==0&&m==0){
        break;
      }
      LineTable table[m][m];

      for(int i=0;i<n;i++){
        int a,b,cost,times;
        cin >> a >> b >> cost >> times;
        table[a-1][b-1].cost = cost;
        table[a-1][b-1].times = times;
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[i][j].cost > table[i][k].cost + table[k][j].cost){
              table[i][j].cost = table[i][k].cost + table[k][j].cost;
            }
          }
        }
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[i][j].times > table[i][k].times + table[k][j].times){
              table[i][j].times = table[i][k].times + table[k][j].times;
            }
          }
        }
      }

      int k,p,q,r;
      cin >> k;
      cin >> p >> q >> r;
      if(r==0){
        cout << table[p-1][q-1].cost;
      }
      else{
        cout << table[p-1][q-1].times;
      }
      for(int i=1;i<k;i++){
        cin >> p >> q >> r;
        if(r==0){
          cout << ' ' <<table[p-1][q-1].cost;
        }
        else{
          cout << ' ' <<table[p-1][q-1].times;
        }
      }
      cout << endl;
    }
    return 0;
}

C++: #include <cstdio>
#include <algorithm>

using namespace std;

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

const int inf = 1e9;

int N, M;
int mc[100][100], mt[100][100];

int main()
{
    while (scanf("%d %d", &N, &M), N || M) {
        fill(mc[0], mc[M], inf);
        fill(mt[0], mt[M], inf);

        rep(i, M) mc[i][i] = mt[i][i] = 0;

        rep(i, N) {
            int a, b, cost, time; scanf("%d %d %d %d", &a, &b, &cost, &time); a--; b--;
            mc[a][b] = mc[b][a] = cost;
            mt[a][b] = mt[b][a] = time;
        }

        rep(k, M) rep(i, M) rep(j, M) {
            chmin(mc[i][j], mc[i][k] + mc[j][k]);
            chmin(mt[i][j], mt[i][k] + mt[j][k]);
        }

        int K; scanf("%d", &K);
        rep(i, K) {
            int p, q, r; scanf("%d %d %d", &p, &q, &r); p--; q--;
            printf("%d\n", r == 0 ? mc[p][q] : mt[p][q]);
        }
    }
}