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 <queue>
#include <vector>
#include <string>
#include <map>
#include <algorithm>

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

using namespace std;

int dijkstra(const vector<vector<int>>& to, const vector<vector<int>>& w, int s, int t, int n) {
  vector<int> weight(n, 1000000000);
  weight[s] = 0;
  priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> q;
  q.push(make_pair(0,s));
  while(!q.empty()){
    auto p = q.top(); q.pop();
    if(p.first > weight[p.second]) continue;
    for(int i = 0;i < to[p.second].size(); ++i) {
      if (weight[to[p.second][i]] > p.first + w[p.second][i]) {
        weight[to[p.second][i]] = p.first + w[p.second][i];
        q.push(make_pair(weight[to[p.second][i]], to[p.second][i]));
      }
    }
  }
  return weight[t];
}


int main() {
  while(1){
    int n,m;
    cin>>n>>m;
    if(!n) break;
    vector<vector<int>> to(m);
    vector<vector<int>> cost(m);
    vector<vector<int>> time(m);
    for (int i = 0; i < n; ++i) {
      int a, b, c, t;
      cin >> a >> b >> c >> t;
      --a;--b;
      to[a].push_back(b);
      to[b].push_back(a);
      cost[a].push_back(c);
      cost[b].push_back(c);
      time[a].push_back(t);
      time[b].push_back(t);
    }
    int k;
    cin >> k;
    for (int i = 0; i < k; ++i) {
      int p,q,r;
      cin >> p >> q >> r;
      --p;--q;
      if (r == 0) {
        cout << dijkstra(to,cost,p,q, m) << endl;
      } else {
        cout << dijkstra(to,time,p,q, m) << endl;
      }
    }
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <cstring>

using namespace std;

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


struct edge {
    int from,to,money,time;
};
int d[101];
vector<edge> E;

int main(){
    int n,m;
    while(cin>>n>>m, n|m){
        E.resize(n);
        for(edge& e:E){
            cin>>e.from>>e.to>>e.money>>e.time;
        }
        int k; cin>>k;
        rep(i,k){
            int a,b,c; cin>>a>>b>>c;
            for(int& x:d) x=1<<30;
            d[a]=0;
            while(1){
                bool end=true;
                for(edge& e:E){
                    rep(dir,2){
                        int cost=(c==0 ? e.money : e.time);
                        if(d[e.to]>d[e.from]+cost){
                            d[e.to]=d[e.from]+cost;
                            end=false;
                        }
                        swap(e.from,e.to);
                    }
                }
                if(end) break;
            }
            cout<<d[b]<<endl;
        }
    }
}

C++: #include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<iostream>
#include<string>
#include<algorithm>
#include<queue>
#include<utility>

using namespace std;

int n,m;

long long gc[110][110];
long long gt[110][110];

void warshallfloyd()
{
	for (int k = 0; k < m; k++)
	{
		for (int i = 0; i < m; i++)
		{
			for (int j = 0; j < m; j++)
			{
				gc[i][j] = min(gc[i][j], gc[i][k] + gc[k][j]);
				gt[i][j] = min(gt[i][j], gt[i][k] + gt[k][j]);
			}
		}
	}
}

int main(void)
{
	while (cin >> n >> m, n || m)
	{

		for (int i = 0; i < m; i++)
		{
			for (int j = 0; j < m; j++)
			{
				gc[i][j] = 9999999;
				gt[i][j] = 9999999;
			}
		}

		for (int i = 0; i < n; i++)
		{
			int a, b, c, t;

			cin >> a >> b >> c >> t;

			a--; b--;

			gc[a][b] = gc[b][a] = c;
			gt[a][b] = gt[b][a] = t;
		}

		warshallfloyd();

		int k;

		cin >> k;

		for (int i = 0; i < k;i++)
		{
			int p, q, r;

			cin >> p >> q >> r;

			p--; q--;

			if (r == 0)
			{
				cout << gc[p][q] << endl;
			}
			else
			{
				cout << gt[p][q] << endl;
			}
		}
	}

	

	return 0;
}

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

const int INF = 1000000000;

int main()
{
	while(true){
		int n, m;
		cin >> n >> m;

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

		int C[100][100];
		int T[100][100];
		for(int i=0; i<m; i++){
			for(int j=0; j<m; j++){
				if(i==j){
					C[i][j] = T[i][j] = 0;
				}
				else{
					C[i][j] = T[i][j] = INF;
				}
			}
		}

		for(int i=0; i<n; i++){
			int a, b, c, t;
			cin >> a >> b >> c >> t;

			C[a-1][b-1] = C[b-1][a-1] = c;
			T[a-1][b-1] = T[b-1][a-1] = t;
		}

		int N,p,q,r;
		int d[100][100];
		cin >> N;
		for(int I=0;I<N;I++){
			cin >> p >> q >> r;
			if(r){
				for(int i=0;i<m;i++){
					for(int j=0;j<m;j++){
						d[i][j]=T[i][j];
					}
				}
			}else{
				for(int i=0;i<m;i++){
					for(int j=0;j<m;j++){
						d[i][j]=C[i][j];
					}
				}
			}
			for(int k=0;k<m;k++){
				for(int i=0;i<m;i++){
					for(int j=0;j<m;j++){
						if(d[i][j]>d[i][k]+d[k][j]){
							d[i][j]=d[i][k]+d[k][j];
						}
					}
				}
			} 
			cout << d[p-1][q-1] << endl;
		}
	}

	return 0;
}