Go: // Warshall–Floyd Algorithm

package main

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

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
				} else {
					c_dist[i][j] = c_matrix[i][j]
				}
				if c_matrix[i][j] == 0{
					c_prev[i][j] = -1
				} else {
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0{
					t_dist[i][j] = INF
				} else {
					t_dist[i][j] = t_matrix[i][j]
				}
				if t_matrix[i][j] == 0{
					t_prev[i][j] = -1
				} else {
					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 <vector>
#include <array>
#include <algorithm>
#include <iterator>
using namespace std;

struct AboutTo;

class Node{
public:
	int aa;
	int Lowest;
	bool IsSelected;
	vector<AboutTo> ToCollection;
	Node(){
		Lowest = 2147483647/2;
		IsSelected = false;
	}
	void Reset(){
		Lowest = 2147483647/2;
		IsSelected = false;
	}
};
struct AboutTo{
	Node* To;
	int Cost;
	int Time;
};

int GetShortest(int a, int b, vector<Node> &aNodeCol, const int IsTime){
	aNodeCol[a].IsSelected = true;
	int TempMin = 2147483647/2;
	int aNode;
	//Node fad;
	for (unsigned int i = 0; i < aNodeCol.size(); ++i){
		if (aNodeCol[i].IsSelected){
			for (unsigned int j = 0; j < aNodeCol[i].ToCollection.size(); ++j){
				if (!(*(aNodeCol[i].ToCollection[j].To)).IsSelected){
					if (IsTime){
						if (TempMin>aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Time){
							TempMin = aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Time;
							aNode = (*(aNodeCol[i].ToCollection[j].To)).aa;
							//fad = *aNodeCol[i].ToCollection[j].To;
						}
					}
					else{
						if (TempMin>aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Cost){
							TempMin = aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Cost;
							aNode = (*(aNodeCol[i].ToCollection[j].To)).aa;
							//fad = *aNodeCol[i].ToCollection[j].To;
						}
					}
				}
			}
		}
	}
	if (b != aNode){
		aNodeCol[aNode].Lowest = TempMin;
		return GetShortest(aNode, b, aNodeCol, IsTime);
	}
	/*if (GoalNode != fad){
		aNodeCol[aNode].Lowest = TempMin;
		return GetShortest(aNode, GoalNode, b, aNodeCol, IsTime);
	}*/
	return TempMin;
}

int main(){
	int n, m;
	cin >> n >> m;
	vector<Node> NodeCollection;
	for (int i = 0; i < m; ++i){
		Node aNode;
		aNode.aa = i;
		NodeCollection.push_back(aNode);
	}

	for (int i = 0; i < n; ++i){
		int a, b, cost, time;
		cin >> a >> b >> cost >> time;
		NodeCollection[a - 1].ToCollection.push_back({ &NodeCollection[b - 1], cost, time });
		NodeCollection[b - 1].ToCollection.push_back({ &NodeCollection[a - 1], cost, time });
	}
	int k;
	cin >> k;
	for (int i = 0; i < k; ++i){
		int p, q, r;
		cin >> p >> q >> r;
		NodeCollection[p - 1].Lowest = 0;
		cout << GetShortest(p - 1, q - 1, NodeCollection, r) << endl;
		for (auto i = NodeCollection.begin(); i != NodeCollection.end(); ++i){
			(*i).Reset();
		}
	}
	cin >> k >> k;
	return 0;
}

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

const int INF = 10000000;

using Mat = std::vector< std::vector<int> >;

void wf(Mat& adj_mat) {
  int n = adj_mat.size();

  for(int i = 0; i < n; ++i) {     // via node
    for(int j = 0; j < n; ++j) {   // start
      for(int k = 0; k < n; ++k) { // terminal
        adj_mat[j][k] = std::min(adj_mat[j][k], adj_mat[j][i] + adj_mat[i][k]);
      }
    }
  }
}

int main() {
  int n, m;
  int a, b, cost, time;

  std::cin >> n >> m;
  Mat cost_table, time_table;
  cost_table.resize(m);
  time_table.resize(m);
  for(int i = 0; i < m; ++i) {
    cost_table.at(i).resize(m);
    time_table.at(i).resize(m);
    for(int j = 0; j < m; ++j){
      cost_table[i][j] = INF;
      time_table[i][j] = INF;
    }
  }

  for(int i = 0; i < n; ++i){
    std::cin >> a >> b >> cost >> time;
    --a, --b;
    cost_table[a][b] = cost_table[b][a] = cost;
    time_table[a][b] = time_table[b][a] = time;
  }

  wf(cost_table);
  wf(time_table);

  // Query
  int k;
  int p, q, r;
  std::cin >> k;
  for(int i = 0; i < k; ++i){
    std::cin >> p >> q >> r;
    --p, --q;
    if (r == 0)
      std::cout << cost_table[p][q] << std::endl;
    else
      std::cout << time_table[p][q] << std::endl;

  }
}

C++: #include<functional>
#include<algorithm>
#include<iostream>
#include<utility>
#include<string>
#include<vector>
#include<cmath>
#include<stack>
#include<queue>
#include<deque>
#include<map>
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,x,n) for(int i=x;i<n;i++)
#define pf push_front
#define pb push_back
#define int long long
using namespace std;
const int INF=1000000007;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
const int N=101;

int cost[N][N];
int tim[N][N];

int bfs(int n,int p,int q,int graph[N][N]){
  vector<int> v(n);
  queue<int> que;
  rep(i,n)v[i]=INF;
  v[p]=0;
  que.push(p);
  int u;
  while(!que.empty()){
    u=que.front(),que.pop();
   
    rep(i,n){
      if(v[i]>v[u]+graph[u][i]){
        v[i]=v[u]+graph[u][i];
        que.push(i);
      }
    }
  }
  return v[q];
}


signed main(){
  int n,m;
  while(cin>>n>>m,n!=0){ 
    rep(i,n)rep(j,n){
      cost[i][j]=(i==j?0:INF);
      tim[i][j]=(i==j?0:INF);
    }
    rep(i,n){
      int a,b,c,t;
      cin>>a>>b>>c>>t;
      a--;b--;
      cost[a][b]=cost[b][a]=c;
      tim[a][b]=tim[b][a]=t;
    }
    int k;
    cin>>k;
    rep(i,k){
      int p,q,r;
      cin>>p>>q>>r;
      p--;q--;
      int ans;
      if(r==0){
        ans=bfs(n,p,q,cost);
      }else{
        ans=bfs(n,p,q,tim);
      }
      cout<<ans<<endl;
    }
  }


  return 0;
}