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 <stdio.h>

int INF = 1000000;

int main(void)
{
	int n, m, a, b, k, t;
	int tcost[105][105], mcost[105][105], node[105], used[105];
	int i, j, min;
	
	while (1){
		scanf("%d %d", &n, &m);
		
		if (n == 0 && m == 0){
			break;
		}
		
		for (i = 0; i < m; i++){
			for (j = 0; j < m; j++){
				mcost[i][j] = INF;
				tcost[i][j] = INF;
			}
		}
		
		for (i = 0; i < n; i++){
			scanf("%d %d", &a, &b);
			a--; b--;
			scanf("%d %d", &mcost[a][b], &tcost[a][b]);
		}
		
		scanf("%d", &k);
		
		for (i = 0; i < k; i++){
			scanf("%d %d %d", &a, &b, &t);
			a--; b--;
			for (j = 0; j < m; j++){
				node[j] = INF;
				used[j] = 0;
			}
			
			node[a] = 0;
			while (1){
				used[a] = 1;
				min = INF;
				
				for (j = 0; j < m; j++){
					if (t == 1){
						if (used[j] == 0 && tcost[a][j] != INF && node[j] > node[a] + tcost[a][j]){
							node[j] = node[a] + tcost[a][j];
						}
						if (used[j] == 0 && min > node[j]){
							min = j;
						}
					}
					else{
						if (used[j] == 0 && tcost[a][j] != INF && node[j] > node[a] + mcost[a][j]){
							node[j] = node[a] + mcost[a][j];
						}
						if (used[j] == 0 && min > node[j]){
							min = j;
						}
					}
				}
				a = min;
				if (a == b){
					break;
				}
			}
			printf("%d\n", node[b]);
		}
	}
	return (0);
}

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

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

const int INF = 1<<28, MAXM = 101, COST = 0, TIME = 1;

int cost[2][MAXM][MAXM];
int d[MAXM][MAXM];

int main()
{
    int n, m, a, b, c, t;
    while(cin >> n >> m)
    {
        REP(2)rep(j,m)rep(k,m)cost[i][j][k] = INF;
        //fill(cost, sizeof(cost), INF);
        REP(n)
        {
            cin >> a >> b >> c >> t;
            a--; b--;
            cost[TIME][a][b] = cost[TIME][b][a] = t;
            cost[COST][a][b] = cost[COST][b][a] = c;
        }

        int k;
        cin >> k;
        int p, q, r;
        rep(s,k)
        {
            cin >> p >> q >> r; p--; q--;

            memset(d, INF , sizeof(d));
            rep(i,m)rep(j,m) d[i][j] = cost[r][i][j];

            rep(l,m)rep(i,m)rep(j,m)
                d[i][j] = min(d[i][j], d[i][l] + d[l][j]);

            cout << d[p][q] << endl;

        }
    }
    return 0;
}

C++: #include <algorithm>
#include <map>
#include <vector>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <cstdlib>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <set>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define IREP(it,array) for(vector<int>::iterator it=array.begin(); it!=array.end(); ++it)
#define SREP(it,array) for(vector<string>::iterator it=array.begin(); it!=array.end(); ++it)

#define MP       make_pair
#define PB       push_back
#define ALL(x)   (x).begin(),(x).end()

const int INF = 1<<29;
const double EPS = 1e-9;
double zero(double d){
  return d < EPS ? 0.0 : d;
}

typedef long long LL;
typedef pair<int,int> P;


int main()
{
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(7);

  int n,m;
  cin >> n >> m;

  vector< vector<int> > cost(m+1, vector<int>(m+1,INF)),
    time(m+1, vector<int>(m+1,INF));

  REP(i,cost.size()){
    cost[i][i] = time[i][i] = 0;
  }

  REP(i,n){
    int a,b,c,t;
    cin >> a >> b >> c >> t;
    cost[a][b] = cost[b][a] = c;
    time[a][b] = time[b][a] = t;
  }

  REP(i,cost.size()){
    REP(j,cost.size()){
      REP(k,cost.size()){
	cost[j][k] = min( cost[j][k], cost[j][i] + cost[i][k] );
	time[j][k] = min( time[j][k], time[j][i] + time[i][k] );
      }
    }
  }

  int k;
  cin >> k;
  REP(_tmp,k){
    int p,q,r;
    cin >> p >> q;
    if(p==0&&q==0)
      return 0;

    cin >> r;
    int res= r ? time[p][q] : cost[p][q];
    cout << res << endl;
  }

  return 0;
}

C++: #include <cstdio>
#include <algorithm>
#include <vector>
#include <utility>
using namespace std;

const int INF = 1<<29;

int n, m, a, b, c, t, k;
int dp[2][101][101];

int main(){
    for(; scanf("%d%d", &n, &m), n||m;){
        for(int x = 0; x <= m; x++){
            fill(dp[0][x], dp[0][x]+m+1, INF);
            fill(dp[1][x], dp[1][x]+m+1, INF);
        }
        for(int x = 0; x <= m; x++){
            dp[0][x][x] = dp[1][x][x] = 0;
        }
        for(int x = 0; x < n; x++){
            scanf("%d%d%d%d", &a, &b, &c, &t);
            dp[0][a][b] = c;
            dp[1][a][b] = t;
        }
        for(int z = 1; z <= m; z++){
            for(int x = 1; x <= m; x++){
                for(int y = 1; y <= m; y++){
                    dp[0][x][y] = min(dp[0][x][y],
                            dp[0][x][z] + dp[0][z][y]);
                    dp[1][x][y] = min(dp[1][x][y],
                            dp[1][x][z] + dp[1][z][y]);
                }
            }
        }
        scanf("%d", &k);
        for(int x = 0; x < k; x++){
            scanf("%d%d%d", &a, &b, &c);
            printf("%d\n", dp[c][a][b]);
        }
    }
    return 0;
}