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 <algorithm>
#define MAX_M 100
#define INF (1<<21)
using namespace std;

int dp_cost[MAX_M][MAX_M];
int dp_time[MAX_M][MAX_M];
int m;

void warshall_froyd(){
  for(int k=0;k<m;k++){
    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
        dp_cost[i][j] = min(dp_cost[i][j], dp_cost[i][k] + dp_cost[k][j]);
        dp_time[i][j] = min(dp_time[i][j], dp_time[i][k] + dp_time[k][j]);
      }
    }
  }
}

int main(){
  int n;
  cin >> n >> m;
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      dp_time[i][j] = (i==j ? 0 : INF);
      dp_cost[i][j] = (i==j ? 0 : INF);
    }
  }

  for(int i=0;i<n;i++){
    int a,b,cost,time;
    cin >> a >> b >> cost >> time;
    a--;
    b--;
    dp_cost[a][b] = cost; dp_cost[b][a] = cost;
    dp_time[a][b] = time; dp_time[b][a] = time;
  }
  
  warshall_froyd();

  int k,p,q,r;
  cin >> k;
  for(int i=0;i<k;i++){
    cin >> p >> q >> r;
    p--; q--;
    cout << (r == 0 ? dp_cost[p][q] : dp_time[p][q]) << endl;
  }
  cin >> p >> q;
  return 0;
}

C++: #include<iostream>
#include<stdio.h>
#include<vector>
#include<stdlib.h>
#include<set>
#include<string>
#include<queue>
#include<map>

#define INF 9999999

using namespace std;

int main(){

	int n, m;
	int a, b, c, t;

	int resultOfCost[110][110] = {0};
	int resultOfTime[110][110] = {0};

	for (;;){
		cin >> n >> m;

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

		
		for (int i = 0; i < m; i++){
			for (int j = 0; j < m; j++){
				if (i != j){
					resultOfCost[i][j] = INF;
					resultOfTime[i][j] = INF;
				}
			}
		}
		
		for (int i = 0; i < n; i++){
			cin >> a >> b >> c >> t;
			a--; b--;
			resultOfCost[a][b] = c;
			resultOfCost[b][a] = c;
			resultOfTime[a][b] = t;
			resultOfTime[b][a] = t;
		}

		for (int y = 0; y < m; y++){
			for (int x = 0; x < m; x++){
				for (int z = 0; z < m; z++){
					resultOfCost[x][z] = min(resultOfCost[x][z], resultOfCost[x][y] + resultOfCost[y][z]);
					resultOfTime[x][z] = min(resultOfTime[x][z], resultOfTime[x][y] + resultOfTime[y][z]);
				}
			}
		}

		int k;
		cin >> k;

		int p, q, r;
		for (int i = 0; i < k; i++){
			cin >> p >> q >> r;
			p--; q--;
			if (r == 0){
				cout << resultOfCost[p][q] << endl;
			}
			else{
				cout << resultOfTime[p][q] << endl;
			}
		}
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define INF INT_MAX/3
#define ALL(a) (a).begin(),(a).end()
#define CLR(a) memset(a,0,sizeof(a))

typedef long long int ll;

using namespace std;

int main(){
    while(true){
	int n,m;
	cin >> n >> m;
	if(n==0&&m==0)break;
	m++;
	vector< vector<int> > dis(m,vector<int>(m,1000000));
	vector< vector<int> > mon(m,vector<int>(m,1000000));
	REP(i,n){
	    int a,b,cost,time;
	    cin >> a >> b >> cost >> time;
	    dis[a][b] = time;
	    dis[b][a] = time;
	    mon[a][b] = cost;
	    mon[b][a] = cost;
	}
	REP(k,m)REP(i,m)REP(j,m){
	    dis[i][j] = min(dis[i][j],dis[i][k]+dis[k][j]);
	    mon[i][j] = min(mon[i][j],mon[i][k]+mon[k][j]);
	}
	cin >> n;
	REP(i,n){
	    int p,q,r;
	    cin >> p >> q >> r;
	    if(r == 0){
		cout << mon[p][q] << endl;
	    }else{
		cout << dis[p][q] << endl;
	    }
	}
    }
    return 0;
}