Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

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
					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<cstdio>
#include<iostream>
#include<cmath>
#include<queue>
 
#define NMAX 3000*2
#define MMAX 100*2
#define TMAX 1000*2
#define CMAX 1000*2
#define KMAX 200*2
 
using namespace std;
 
int main(){
    std::ios_base::sync_with_stdio(false);
 
    int n,m;
    int a,b,time,cost;
    int data[MMAX][MMAX][3];
    int k;
    int p,q,r;
    int dp[MMAX];
    queue<int> now;
 
    while(1){
        for(int i=0;i<MMAX;i++){
            for(int j=0;j<MMAX;j++){
                for(int k=0;k<3;k++){
                    data[i][j][k]=-1;
                }
            }
        }
 
        for(int i=0;i<MMAX;i++){
            dp[i]=-1;
        }
 
        cin>>n>>m;
        if(n==0&&m==0) break;
        for(int i=0;i<n;i++){
            cin>>a>>b>>cost>>time;
            data[a][b][1]=time;
            data[b][a][1]=time;
            data[a][b][0]=cost;
            data[b][a][0]=cost;
        }
 
        cin>>k;
        for(int i=0;i<k;i++){
            cin>>p>>q>>r;
            now.push(p);
            dp[p]=0;
            while(!now.empty()){
                for(int i=0;i<n;i++){
                    if(data[now.front()][i][r]!=-1){
                        if(dp[i]==-1||dp[i]>dp[now.front()]+data[now.front()][i][r]){
                            dp[i]=dp[now.front()]+data[now.front()][i][r];
                            now.push(i);
                        }
                    }
                }
                now.pop();
            }
            cout<<dp[q]<<endl;
        }
 
    }
 
 
 
    return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <sstream>
#include <stdio.h>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <math.h>
#include <utility>
#include <string>
#include <ctype.h>
#include <cstring>
#include <cstdio>
#include <sstream>
#include <functional>

using namespace std;

#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define INF 114514810
#define ll long long
//#define scanf scanf_s

int cost[2][101][101];

int main()
{
	int n, m;
	while (cin >> n >> m) 
	{
		if (!n&&!m) break;
		REP(k,2)REP(i, 101)REP(j, 101)
		{
				cost[k][i][j] = INF;
		}
		
		REP(i, n)
		{
			int a, b, c, t;
			cin >> a >> b >> c >> t;
			a--; b--;
			cost[0][a][b] = cost[0][b][a] = c;
			cost[1][a][b] = cost[1][b][a] = t;
		}

		REP(l,2)REP(i, m)REP(j, m)REP(k, m)
		{
			cost[l][i][j] = min(cost[l][i][j], cost[l][i][k] + cost[l][k][j]);
		}
		int k;
		cin >> k;
		REP(i, k)
		{
			int p, q, r;
			cin >> p >> q >> r;
			p--; q--;
			if (r == 0) cout << cost[0][p][q] << endl;
			else cout << cost[1][p][q] << endl;
		}
	}
	return 0;
}

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

using namespace std;

int main(int argc, char **argv)
{
  int c[100][100], t[100][100], n, m, a, b, u, v;

  while(1){
    cin >> n >> m;

    if(n == 0 && m == 0){
      break;
    }

    fill(&c[1][1], &c[m][m], 999);
    fill(&t[1][1], &t[m][m], 999);

    for(int i = 1; i <= m; i++){
      c[i][i] = t[i][i] = 0;
    }

    for(int i = 0; i < n; i++){
      cin >> a >> b >> u >> v;
      c[a][b] = c[b][a] = u;
      t[a][b] = t[b][a] = v;
    }

    for(int k = 1; k <= m; k++){
      for(int i = 1; i <= m; i++){
	for(int j = 1; j <= m; j++){
	  c[i][j] = (c[i][j] < c[i][k]+c[k][j])? c[i][j] : c[i][k]+c[k][j];
	  t[i][j] = (t[i][j] < t[i][k]+t[k][j])? t[i][j] : t[i][k]+t[k][j];
	}
      }
    }
    cin >> n;
    while(n--){
      cin >> a >> b >> u;
      if(u == 0){
	cout << c[a][b] << endl;
      } else {
	cout << t[a][b] << endl;
      }
    }
  }

  return 0;
}