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]
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[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>
#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;
}

C++: #include<stdio.h>
#include<algorithm>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <iostream>
#include <functional>
#include <time.h>
using namespace std;
clock_t fi, endtime;

const int INF = 2147483647;
const int r_c = 0;
const int r_t = 1;
const int MAX_V = 100;
const int MAX_E = 6000;


int main()
{
	while (1) {
		int n, m, a, b, c, t;
		int k, p, q, r;

		int wft[MAX_V][MAX_V] = { 0 };
		int wfc[MAX_V][MAX_V] = { 0 };

		scanf("%d %d", &n, &m);
		if (n == 0 && m == 0) break;
		for (int i = 0; i < m; ++i) {
			for (int j = 0; j < m; ++j) {
				wfc[i][j] = INF; wft[i][j] = INF;
			}
		}
		for (int i = 0; i < n; ++i) {
			scanf("%d %d %d %d", &a, &b, &c, &t);
			wft[a - 1][b - 1] = t;  wft[b - 1][a - 1] = t;
			wfc[a - 1][b - 1] = c;  wfc[b - 1][a - 1] = c;
		}
		for (int k = 0; k < m; ++k) {
			for (int i = 0; i < m; ++i) {
				for (int j = 0; j < m; ++j) {
					if (wft[i][j] > wft[i][k] + wft[k][j]) { wft[i][j] = wft[i][k] + wft[k][j]; }
					if (wfc[i][j] > wfc[i][k] + wfc[k][j]) { wfc[i][j] = wfc[i][k] + wfc[k][j]; }
				}
			}
		}
		scanf("%d", &k);
		int ans = 0;
		for (int i = 0; i < k; ++i) {
			scanf("%d %d %d", &p, &q, &r);
			if (r == 0) { ans = wfc[p - 1][q - 1]; }
			else { ans = wft[p - 1][q - 1]; }
			printf("%d\n", ans);
		}
	}
}

C++: #include <cstdio>
#include <vector>
#include <queue>
#include <algorithm>

#define MAX_M 100
#define INF 1145141919

class edge{
public:
    int to;
    int cost;
    int time;
};

typedef std::pair<int, int> P;

int n, m, a, b, c, t, k, s, g, r;
int value[2][MAX_M + 1];
std::vector<edge> G[MAX_M + 1];


int ret(edge e){
    if(r == 0) return e.cost;
    return e.time;
}

void dij(){
    std::fill(value[r], value[r] + MAX_M + 1, INF);
    value[r][s] = 0;

    std::priority_queue<P, std::vector<P>, std::greater<P> > que;
    que.push(P(0, s));

    while(!que.empty()){
        P p = que.top(); que.pop();
        if(value[r][p.second] < p.first) continue;

        for(int i = 0; i < G[p.second].size(); i++){
            edge e = G[p.second][i];
            int u = ret(e);
            if(value[r][e.to] > value[r][p.second] + u){
                value[r][e.to] = value[r][p.second] + u;
                que.push(P(value[r][e.to], e.to));
            }
        }
    }

    printf("%d\n", value[r][g]);
}

int main(){

    while(scanf("%d %d", &n, &m) != EOF){
        if(n == 0 && m == 0) break;

        for(int i = 0; i < n; i++){
            scanf("%d %d %d %d", &a, &b, &c, &t);
            a--; b--;


            edge e1, e2;
            e1.to   = b; e2.to = a;
            e1.cost = c; e2.cost = c;
            e1.time = t; e2.time = t;
            G[a].push_back(e1);
            G[b].push_back(e2);
        }


        scanf("%d", &k);
        for(int i = 0; i < k; i++){
            scanf("%d %d %d", &s, &g, &r);
            s--; g--;

            dij();
        }
    }

    return 0;
}