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 <algorithm>
#define INF 1000000000
using namespace std;

int cost[2][101][101];

int n,m;

void warshall_floyd(){
  for(int i = 1 ; i < m ; i++ ){
    for(int j = 1 ; j < m ; j++ ){
      for(int k = 1 ; k < m ; k++ ){
	cost[0][i][j] = min(cost[0][i][j],cost[0][i][k] + cost[0][k][j]);
	cost[1][i][j] = min(cost[1][i][j],cost[1][i][k] + cost[1][k][j]);
      }
    }
  }
}

void input(){
  for(int i = 0 ; i < n ; i++ ){
    int a,b,c,d;
    cin >> a >> b >> c >> d;
    cost[0][a][b] = cost[0][b][a] = c;
    cost[1][a][b] = cost[1][b][a] = d;  
  }
}

void init(){
  for(int i = 1  ; i < m ; i++ ){
    for(int j = 1  ; j < m ; j++ ){
      if(i == j){
	cost[0][i][j] = 0;
	cost[1][i][j] = 0;
      }else{
	cost[0][i][j] = INF; 
	cost[1][i][j] = INF; 
      }
    }
  }
}

int main(){

  while(cin >> n >> m , n+m ){
    m++;
    init();
    input();
    warshall_floyd();
    int k;
    cin >> k;
    for(int i = 0 ; i < k ; i++ ){
      int from,to,r;
      cin >> from >> to >> r; 
      cout << cost[r][from][to] << endl;
    }
  }
  return 0;
}

C++: #include <bits/stdc++.h>
#define r(i,n) for(int i=0;i<n;i++)
#define INF 1<<29
using namespace std;
main(){
  int m,n;
  while(cin>>m>>n,n){
    int a1[n][n],a2[n][n],q,w,e,r;
    r(i,n)r(j,n){
      if(i==j)a2[i][j]=a1[i][j]=0;
      else a2[i][j]=a1[i][j]=INF;
    }
    while(m--){
      scanf("%d%d%d%d",&q,&w,&e,&r);q--;w--;
      a1[q][w]=a1[w][q]=e;
      a2[q][w]=a2[w][q]=r;
    }
    r(k,n)r(i,n)if(a1[i][k]!=INF||a2[i][k]!=INF)r(j,n)
    if(a1[j][k]!=INF&&a1[i][k]!=INF||a2[j][k]!=INF&&a2[i][k]!=INF){
      a1[i][j]=min(a1[i][j],a1[i][k]+a1[k][j]);
      a2[i][j]=min(a2[i][j],a2[i][k]+a2[k][j]);
    }
    cin>>e;
    while(e--){
      scanf("%d%d%d",&q,&w,&r);q--;w--;
      if(r)cout<<a2[q][w]<<endl;
      else cout<<a1[q][w]<<endl;
    }
  }
}

C++: #include<iostream>
#define INF 100000000
using namespace std;
/*int min(int a,int b){
  return a<b?a:b;
  }*/
int main(){
  int n,m;
  while(cin>>n>>m){
    if(n==0&&m==0) break;
    int d0[m+1][m+1],d1[m+1][m+1];
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
    d0[i][j] = INF;
    d1[i][j] = INF;
      }
    }
    int a,b,cost,time;
    for(int i=0;i<n;i++){
      cin >> a >> b >> cost >> time;
      d0[a][b] = cost;
      d0[b][a] = cost;
      d1[a][b] = time;
      d1[b][a] = time;
    }
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
    for(int k=1;k<=m;k++){
      d0[j][k] = min(d0[j][k],d0[j][i]+d0[i][k]);
      d1[j][k] = min(d1[j][k],d1[j][i]+d1[i][k]);
    }
      }
    }
    int s,p,q,r;
    cin >> s;
    for(int i=0;i<s;i++){
      cin >> p >> q >> r;
      if(p==q) cout << 0 << endl;
      else if(r==0) cout << d0[p][q] << endl;
      else cout << d1[p][q] << endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <map>
#include <cstdio>
#include <cstdlib>
using namespace std;

typedef pair<int,int> P;

const int MAX_V = 101;
const int INF = 1000000009;
struct edge { int to, cost, time; };
vector<edge> G[MAX_V];
int dist[MAX_V];

int dijkstra(int s, int t, int type) {
	fill(dist, dist+MAX_V, INF);
	dist[s] = 0;
	priority_queue<P, vector<P>, greater<P> > que;
	que.push(P(0, s));
	while(!que.empty()) {
		P n = que.top(); que.pop();
		int v = n.second;
		if(v == t) return dist[v];

		for(int i=0; i<G[v].size(); i++) {
			edge& e = G[v][i];
			if(type == 0) {
				if(dist[e.to] > dist[v] + e.cost) {
					dist[e.to] = dist[v] + e.cost;
					que.push(P(dist[e.to], e.to));
				}
			} else {
				if(dist[e.to] > dist[v] + e.time) {
					dist[e.to] = dist[v] + e.time;
					que.push(P(dist[e.to], e.to));
				}
			}
		}
	}
	return INF;
}

int M, N, K;
int a, b, c, t;
int p, q, r;


int main() {
	while(scanf("%d%d", &N, &M), N|M) {
		for(int i=0; i<MAX_V; i++) G[i].clear();

		for(int i=0; i<N; i++) {
			scanf("%d%d%d%d", &a, &b, &c, &t);
			edge e = { b, c, t };
			G[a].push_back(e);
		}

		scanf("%d", &K);
		for(int i=0; i<K; i++) {
			scanf("%d%d%d", &p, &q, &r);
			int d = dijkstra(p, q, r);
			printf("%d\n", d);
		}
	}
}

C++: #define _CRT_SECURE_NO_WARNINGS

#include<fstream>
#include<iostream>
#include<string>
#include<iomanip>
#include<list>
#include<math.h>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
#include<utility>

using namespace std;

int cost[3000][3000];
int time_data[3000][3000];


int main(){
	int n, m;


	while (cin >> n >> m && (n != 0 && m != 0)) {
		int min_ = 1000000000; // 答えの最小値
		int min_num = 1; // 答えの町

		int from, to, time_, cost_;
		int k;
		int k_from, k_to, info;

		for (int i = 0; i < 3000; i++) {
			for (int j = 0; j < 3000; j++) {
				cost[i][j] = 100000000;
				time_data[i][j] = 100000000;
			}
		}
		for (int i = 0; i < 3000; i++) {
			cost[i][i] = 0;
		}
		for (int i = 0; i < n; i++) {
			cin >> from >> to >> cost_ >> time_;
			cost[from][to] = cost_;
			cost[to][from] = cost_;
			time_data[from][to] = time_;
			time_data[to][from] = time_;
		}
		for (int k = 1; k <= m; k++) {
			for (int i = 1; i <= m; i++) {
				for (int j = 1; j <= m; j++) {
					cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);

					time_data[i][j] = min(time_data[i][j], time_data[i][k] + time_data[k][j]);
				}
			}
		}
		// 答えを求める
		cin >> k;
		for (int i = 0; i < k; i++) {
			cin >> k_from >> k_to >> info;
			if (info == 0) {
				cout << cost[k_from][k_to] << endl;
			} else {
				cout << time_data[k_from][k_to] << endl;
			}
		}
		
  }
	return 0;
}