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 <iomanip>
#include <sstream>
#include <stdio.h>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <math.h>
#include <utility>
#include <string>
#include <ctype.h>
#include <cstring>
#include <cstdio>
#include <sstream>
#include <functional>

using namespace std;

#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define INF 114514810
#define ll long long
//#define scanf scanf_s


int main()
{

	int cost[101][101];
	int time_[101][101];

	while (1)
	{
		int n, m;
		cin >> n >> m; if (n == 0 && m == 0) break;
		REP(i, 101)REP(j, 101)
		{
			if (i == j)
			{
				cost[i][j] = 0;
				time_[i][j] = 0;
			}
			else
			{
				cost[i][j] = INF;
				time_[i][j] = INF;
			}
		}
		
		REP(i, n)
		{
			int a, b, c, t;
			cin >> a >> b >> c >> t;
			a--; b--;
			cost[a][b] = cost[b][a] = c;
			time_[a][b] = time_[b][a] = t;
		}

		REP(i, m)REP(j, m)REP(k, m)
		{
			cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
			time_[i][j] = min(time_[i][j], time_[i][k] + time_[k][j]);
		}
		int k;
		cin >> k;
		REP(i, k)
		{
			int p, q, r;
			cin >> p >> q >> r;
			p--; q--;
			if (r == 0) cout << cost[p][q] << endl;
			else cout << time_[p][q] << endl;
		}
	}
	return 0;
}

C++: #include <stdio.h>
#include <limits.h>

const int INF = INT_MAX;

int main(void)
{
	int n, m, a, b, k, t;
	int tcost[105][105], mcost[105][105], node[105], used[105];
	int i, j, min;
	
	while (1){
		scanf("%d %d", &n, &m);
		
		if (n == 0 && m == 0){
			break;
		}
		
		for (i = 0; i < m; i++){
			for (j = 0; j < m; j++){
				mcost[i][j] = INF;
				tcost[i][j] = INF;
			}
		}
		
		for (i = 0; i < n; i++){
			scanf("%d %d", &a, &b);
			a--; b--;
			scanf("%d %d", &mcost[a][b], &tcost[a][b]);
		}
		
		scanf("%d", &k);
		
		for (i = 0; i < k; i++){
			scanf("%d %d %d", &a, &b, &t);
			a--; b--;
			for (j = 0; j < m; j++){
				node[j] = INF;
				used[j] = 0;
			}
			
			node[a] = 0;
			while (1){
				used[a] = 1;
				min = INF;
				
				for (j = 0; j < m; j++){
					if (t == 1){
						if (used[j] == 0 && tcost[a][j] != INF && node[j] > node[a] + tcost[a][j]){
							node[j] = node[a] + tcost[a][j];
						}
						if (used[j] == 0 && min > node[j]){
							min = j;
						}
					}
					else{
						if (used[j] == 0 && tcost[a][j] != INF && node[j] > node[a] + mcost[a][j]){
							node[j] = node[a] + mcost[a][j];
						}
						if (used[j] == 0 && min > node[j]){
							min = j;
						}
					}
				}
				a = min;
				if (a == b){
					break;
				}
			}
			printf("%d\n", node[b]);
		}
	}
	return (0);
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 1000000007

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<double, double> PD;
typedef pair<string, ll> PS;
typedef vector<ll> V;

struct edge{
	int to, cost, time;
	edge(int to, int cost, int time) :to(to), cost(cost), time(time){};
};

int n, m, a, b, cost, time, k, s, g, f;

ll mincost[1000], mintime[1000];
vector<edge> G[1000];

void dijkstra0(int start){
	fill(mincost, mincost + 1000, INF);
	mincost[start] = 0;
	priority_queue<P> que;
	que.push(P(0, start));

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

		for (int i = 0; i < G[v].size(); i++){
			edge e = G[v][i];
			if (mincost[e.to] > mincost[v] + e.cost){
				mincost[e.to] = mincost[v] + e.cost;
				que.push(P(mincost[e.to], e.to));
			}
		}
	}
}

void dijkstra1(int start){
	fill(mintime, mintime + 1000, INF);
	mintime[start] = 0;
	priority_queue<P> que;
	que.push(P(0, start));

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

		for (int i = 0; i < G[v].size(); i++){
			edge e = G[v][i];
			if (mintime[e.to] > mintime[v] + e.time){
				mintime[e.to] = mintime[v] + e.time;
				que.push(P(mintime[e.to], e.to));
			}
		}
	}
}

int main(){
	while (cin >> n >> m&&n + m){
		REP(i, n){
			cin >> a >> b >> cost >> time;
			G[a].push_back(edge(b, cost, time));
			G[b].push_back(edge(a, cost, time));
		}
		cin >> k;
		REP(i, k){
			cin >> s >> g >> f;
			if (f == 0){
				dijkstra0(s);
				cout << mincost[g] << endl;
			}
			else{
				dijkstra1(s);
				cout << mintime[g] << endl;
			}
		}
	}
}