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

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) (r).begin(),(r).end()
#define gsort(st,en) sort((st),(en),greater<int>())
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using dict = map<string,int>;
using pii = pair<int,int> ;

const int mod = 1000000007;
constexpr int imax = ((1<<30)-1)*2+1 ;
constexpr int inf = 100000000;
constexpr double PI = acos(-1.0) ;
double eps = 1e-10 ;
const int dy[] = {-1,0,1,0};
const int dx[] = {0,-1,0,1};

inline bool value(int x,int y,int w,int h){
  return (x >= 0 && x < w && y >= 0 && y < h);
}

template<typename T>
void Unique(vector<T> &v){
  sort(all(v));
  v.erase(unique(all(v)),v.end());
}

template<typename T>
T ston(string& str, T n){
  istringstream sin(str) ;
  T num ;
  sin >> num ;
  return num ;
}

void Ans(bool f){
  if(f) cout << "YES"<<endl;
  else cout << "NO"<<endl;
}

struct Edge{
  int to;
  long long cost;
};

struct NODE{
  int pos;
  long long cost;
};
bool operator < (const NODE &a,const NODE &b){
  return a.cost > b.cost;
}

int N;
const ll INF = 1e15;
vector<ll> dijkstra(vector<Edge> g[110], int s){
  priority_queue<NODE> Q;
  Q.push({s,0});
  vector<ll> res(N+2,INF);
  while(Q.size()){
    NODE q= Q.top();Q.pop();
    if(res[q.pos] == INF){
      res[q.pos] = q.cost;
    }
    else{
      continue;
    }
    for(auto n : g[q.pos]){
      Q.push({n.to,q.cost+n.cost});
    }
  }
  return res;
}
int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n,m;
  while(cin>>N>>m&&N&&m){
    int a,b,c,d;
    vector<Edge> g[110],rg[110];
    rep(i,N){
      cin >> a >> b >> c >> d;
      g[a].push_back({b,c});
      rg[a].push_back({b,d});
      g[b].push_back({a,c});
      rg[b].push_back({a,d});
    }
    int k,p,q,r ;
    cin >> k;
    vector<ll> ansd[N+1],anst[N+1];
    rep(i,N){
      ansd[i+1] = dijkstra(g,i+1);
      anst[i+1] = dijkstra(rg,i+1);
    }
    rep(i,k){
      cin >> p >> q >> r;
      if(r){
        cout << anst[p][q]<<endl;
      }
      else
      {
        cout << ansd[p][q]<<endl;
      }
    }
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <string.h>
#include <time.h>

using namespace std;

static const int TYPE_COST =0;
static const int TYPE_TIME =1;

class station{
public:
	int cost;
	bool visited;
	vector<int> edge_to;
	vector<int> edge_cost;
	vector<int> edge_time;
	
	 public:
		station() :  cost(-1), visited(false){}
		void add_to(int to, int cost, int time)
		{
			this->edge_to.push_back(to);
			this->edge_cost.push_back(cost);
			this->edge_time.push_back(time);
		}
};

int dijkstra(station* sta, int size, int from, int to, int type);
bool contain(vector<station> sta, station elem);
void reset(station* sta, int size);

int main(int argc, char** argv)
{
	while( 1 ){
		int n, m, from, to, cost, time, type;
		cin >> n;
		cin >> m;
		if(n==0 && m==0) break;
		
		station sta[m];
		for(int i=0; i<m; i++){
			sta[i] = station();
		}
		
		for(int i=0; i<n; i++){
			cin >> from;
			cin >> to;
			cin >> cost;
			cin >> time;
			sta[from-1].add_to(to-1, cost, time);
		}
		cin >> n;
		for(int i=0; i<n; i++){
			cin >> from;
			cin >> to;
			cin >> type;
			clock_t t1 = clock();
			cout << dijkstra(sta, m, from-1, to-1, type) << endl;
			clock_t t2 = clock();
			//cout << "Time : "  << t2 - t1<< " (msec)" << endl;
			reset(sta, m);
		}
	}
	
	return 0;
}

int dijkstra(station* sta, int size, int start, int goal, int type)
{
	int to, cost;
	station done;
	vector<station> q;
	sta[start].cost = 0;
	q.push_back(sta[start]);
	
	while(!q.empty()){
		done = q[0];
		q.erase(q.begin());
		done.visited = true;
		
		for(int i=0; i<done.edge_to.size(); i++){
			to = done.edge_to[i];
			if(type==TYPE_COST) cost = done.cost + done.edge_cost[i];
			if(type==TYPE_TIME) cost = done.cost + done.edge_time[i];
			if(sta[to].cost < 0 || cost < sta[to].cost){
				sta[to].cost = cost;
				//if(!contain(q, sta[to])){
					q.push_back(sta[to]);
				//}
			}
		}
	}
	
	return sta[goal].cost;
}

bool contain(vector<station> sta, station elem)
{
	int size = sta.size();
	bool is_match = false;
	for(int i=0; i<size; i++){
		if(memcmp(&sta[i], &elem, sizeof(station)) == 0){
			is_match = true;
			break;
		}
	}
	return is_match;
}

void reset(station* sta, int size)
{
	for(int i=0; i<size; i++){
		sta[i].visited = false;
		sta[i].cost = -1;
	}
}