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>
#include <string>
#include <vector>
#include <queue>
#include <bitset>
#include <set>
#include <map>
#include <stack>

#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,b,n) for(int i=b;i<n;i++)
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

const float PI = 3.1415926;
static const int INFTY = (1<<30);

using namespace std;

typedef long long ll;
typedef long double ld;

int n, m, p, q, r;
int C[101][101], V[101][101];

void floyd() {
  rep(k,m) {
    rep(i,m) {
      if (C[i][k] == INFTY) continue;
      rep(j,m) {
        if (C[k][j] == INFTY) continue;
        C[i][j] = min(C[i][j], C[i][k] + C[k][j]);
      }
    }
  }
  rep(k,m) {
    rep(i,m) {
      if (V[i][k] == INFTY) continue;
      rep(j,m) {
        if (V[k][j] == INFTY) continue;
        V[i][j] = min(V[i][j], V[i][k] + V[k][j]);
      }
    }
  }
}

int main() {
  while(cin >> n >> m, n) {
    rep(i, m) rep(j, m) {
      C[i][j] = ((i==j)?0:INFTY);
      V[i][j] = ((i==j)?0:INFTY);
    }
    
    rep(i, n) {
      int tmp_i, tmp_j, ti, co;
      cin >> tmp_i >> tmp_j >> co >> ti;
      C[tmp_i-1][tmp_j-1] = co;
      V[tmp_i-1][tmp_j-1] = ti;
    }

    floyd();

    int k;
    cin >> k;

    rep(i,k) {
      cin >> p >> q >> r;
      if(r == 0)
        cout << C[p-1][q-1] << endl;
      else
        cout << V[p-1][q-1] << endl;
    }
  }
  
  return 0;
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int dp[105][105][2], n, m;

void solve(int dp[][105][2], int st, int en, int d){
    rep(i, n){
        rep(j, n){
            rep(k, n){
                dp[i][j][d] = min(dp[i][k][d] + dp[k][j][d], dp[i][j][d]);
            }
        }
    }
}

int main(){
    int k;
    int a, b, c, d;
    int st, en, de;
    rep(i, 105)
        rep(j, 105)
            rep(k, 2)
                dp[i][j][k] = 2 << 24;

    while(cin >> n >> m, n||m){
        rep(i, n){
            cin >> a >> b >> c >> d;
            dp[a][b][0] = c; dp[b][a][0] = c;
            dp[a][b][1] = d; dp[b][a][1] = d;
        }
        cin >> k;
        solve(dp, st, en, 0);
        solve(dp, st, en, 1);
        rep(i, k){
            cin >> st >> en >> de;
            cout << dp[st][en][de] << endl;
        }
    }
}

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

using namespace std;

const int INF=1e9;

//struct edge{int to,cost,time;};
struct edge{int cost,time;};

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

	//vector<edge> es[n];
	edge es[m][m];
	for(int i=0;i<m;i++)for(int j=0;j<m;j++) es[i][j] = (edge){INF,INF};

	int a,b,cost,time;
	for(int i=0;i<n;i++){
		cin >> a >> b >> cost >> time;
	//	es[a].emplace_back((edge){b,cost,time});
		es[a-1][b-1] = (edge){cost,time};
		es[b-1][a-1] = es[a-1][b-1];
	}

	int d_cost[m][m];
	int d_time[m][m];
	for(int i=0;i<m;i++){
		for(int j=0;j<m;j++){
			d_cost[i][j] = es[i][j].cost;
			d_time[i][j] = es[i][j].time;
		}
	}

	for(int k=0;k<m;k++){
		for(int i=0;i<m;i++){
			for(int j=0;j<m;j++){
				d_cost[i][j] = min(d_cost[i][j],d_cost[i][k] + d_cost[k][j]);
				d_time[i][j] = min(d_time[i][j],d_time[i][k] + d_time[k][j]);
			}
		}
	}

	int k;
	cin >> k;
	for(int n=0;n<k;n++){
		int p,q,r;
		cin >> p >> q >> r;

		if(r==0) cout << d_cost[p-1][q-1] << "\n";
		else	cout << d_time[p-1][q-1] << "\n";
	}

	return 0;
}

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

#define INF 1e9

int cost[101][101];
int time[101][101];
int cost_d[101];
int time_d[101];
bool used[101];
int V;
int E;

void cost_dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		cost_d[i] = INF;
		used[i] = false;
	}
	cost_d[s] = 0;
	
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && (v == -1 || cost_d[u] < cost_d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			if (cost[v][u] != -1) {
				cost_d[u] = min(cost_d[u], cost_d[v] + cost[v][u]);
			}
		}

	}
}
void time_dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		time_d[i] = INF;
		used[i] = false;
	}
	time_d[s] = 0;

	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] &&( v == -1 || time_d[u] < time_d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			if (cost[v][u] != -1) {
				time_d[u] = min(time_d[u], time_d[v] + cost[v][u]);
			}
		}

	}
}

int main() {


	while (cin >> E >> V, (E != 0 && V != 0)) {
		for (int i = 0; i < V; i++) {
			for (int j = 0; j < V; j++) {
				cost[i][j] = -1;
				time[i][j] = -1;
			}
		}
		
		for (int i = 0; i < E; i++) {
			int a, b,c,t;
			cin >> a >> b>>c>>t;
			cost[a - 1][b - 1] = cost[b - 1][a - 1] = c;
			time[a - 1][b - 1] = time[b - 1][a - 1] = t;
		}
	
		int k;//クエリの数
		cin >> k;
		
		for(int i=0;i<k;i++){
			int p, q, r;
			cin >> p>>q>>r;
			
			//cost
			if (r == 0) {
				cost_dijkstra(p-1);
				cout << cost_d[q-1] << endl;
			}
			//time
			else if(r==1){

				time_dijkstra(p-1);
				cout << time_d[q-1] << endl;
			}
			
		}
	}
	return 0;
}