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 <bits/stdc++.h>
using namespace std;

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

#define pb push_back
#define rep(i, a, n) for(int i = (a); i < (n); i++)
#define dep(i, a, n) for(int i = (a); i >= (n); i--)
#define mod 1e9+7

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

struct edge {int to, cost, time;};

int main() {
  int n, m;
  while(cin >> n >> m) {
    if(!n && !m) return 0;
    vector<edge> ra[101];

    rep(i, 0, n) {
      int a, b, c, t;
      cin >> a >> b >> c >> t;
      edge f, g;
      f.to = b, g.to = a, f.cost = c, g.cost = c, f.time = t, g.time = t;
      ra[a].pb(f);
      ra[b].pb(g);
    }

    int k;
    cin >> k;
    rep(i, 0, k) {
      int s, e, r;
      cin >> s >> e >> r;
      int si[101];
      priority_queue<P, vector<P>, greater<P> > que;
      fill(si, si + 101, INT_MAX);
      si[s] = 0;
      que.push(P(0, s));
      while(!que.empty()) {
        P p = que.top();
        que.pop();
        int v = p.second;
        if(si[v] < p.first) continue;
        rep(i, 0, ra[v].size()) {
          edge ed = ra[v][i];
          if(si[ed.to] > si[v] + (r ? ed.time : ed.cost)) {
            si[ed.to] = si[v] + (r ? ed.time : ed.cost);
            que.push(P(si[ed.to], ed.to));
          }
        }
      }

      cout << si[e] << endl;
    }
  }
}

C++: #include<iostream>
#include<algorithm>
#define MAX 1000000
using namespace std;
int main(){
	int n, m, a, b, cost, ti, k, p, q, r, point = 0;
	int cost_[101][101], time_[101][101], k_[101];
	for (int i = 0; i < 101; i++){
		for (int l = 0; l < 101; l++){
			cost_[i][l] = MAX;
			time_[i][l] = MAX;
		}
	}
	cin >> n >> m;
	while (n != 0 && m != 0){
		for (int i = 0; i < n; i++){
			cin >> a >> b >> cost >> ti;
			cost_[a][b] = cost;
			time_[a][b] = ti;
		}
		cin >> k;
		for (int i = 0; i < k; i++){
			cin >> p >> q >> r;
			k_[point] = p;
			k_[point + 1] = q;
			k_[point + 2] = r;
			point += 3;
		}point = 0;
		for (int i = 1; i <= m; i++){
			for (int j = 1; j <= m; j++){
				for (int o = 1; o <= m; o++){
					if (cost_[j][i] != MAX && cost_[i][o] != MAX &&
						time_[j][i] != MAX && time_[i][o] != MAX){
						cost_[j][o] = min(cost_[j][o], cost_[j][i] + cost_[i][o]);
						time_[j][o] = min(time_[j][o], time_[j][i] + time_[i][o]);
					}
				}
			}
		}
		for (int i = 0; i < k; i++){
			if (k_[point + 2] == 0){
				cout << cost_[k_[point]][k_[point + 1]] << endl;
			}
			else cout << time_[k_[point]][k_[point + 1]] << endl;
			point += 3;
		}
		cin >> n >> m;
	}
	return 0;
}

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

using namespace std;




int main()
{
	while(true)
	{
int timedate[2][105][105];
int n,m;
    memset(timedate,0,sizeof(timedate));
	scanf("%d%d",&n,&m);
	if(n==0&&m==0)break;
	int a, b, cost,time;
	for(int i=0;i<n;i++)
	{
		scanf("%d%d%d%d",&a,&b,&cost,&time);
		timedate[0][a][b]=cost;
		timedate[0][b][a]=cost;
		timedate[1][a][b]=time;
		timedate[1][b][a]=time;
	}
	int k;
	scanf("%d",&k);
	for(int i=0;i<k;i++)
	{
		int p,q,r;
		int date[105];
		int omin=1000000,jmin;
		fill(date,date+100,-1);
		scanf("%d%d%d",&p,&q,&r);
		date[p]=0;
		
			for(int u=1;u<100;u++)
			{
			omin=1000000;
			jmin=0;
		for(int j=1;j<100;j++)
		{
			if(date[j]!=-1)
			{
				for(int o=1;o<101;o++)
				{
					if(timedate[r][j][o]!=0&&o!=-1&&omin>date[j]+timedate[r][j][o]&&date[o]==-1)
					{
						omin=date[j]+timedate[r][j][o];
						jmin=o;
					}
				}
			}
		}
		date[jmin]=omin;
			}
		printf("%d\n",date[q]);
	}
	}
	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 main()
{

	int cost[101][101];
	int time_[101][101];

	while (1)
	{
		int n, m;
		cin >> n >> m; if (n == 0 && m == 0) break;
		REP(i, 101)REP(j, 101)
		{
			if (i == j)
			{
				cost[i][j] = 0;
				time_[i][j] = 0;
			}
			else
			{
				cost[i][j] = INF;
				time_[i][j] = INF;
			}
		}

		REP(i, 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;
		}

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