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>
using namespace std;
#define INFTY (1<<21)
#define MAX 100
#define rep(i, n) for ( int i = 0; i < (int)n; i++)

void floyd(int m, int C[MAX][MAX], int T[MAX][MAX]){
    rep(k, m) rep(i, m) rep(j, m){
	C[i][j] = min( C[i][j], C[i][k] + C[k][j] );
	T[i][j] = min( T[i][j], T[i][k] + T[k][j] );
    }
}

main(){
    int n, m, a, b, c, t, k, q, C[MAX][MAX], T[MAX][MAX];
    while( cin >> n >> m && n && m){
	rep(i, m) rep(j, m) { C[i][j] = T[i][j] = INFTY; }
	rep(i, n){
	    cin >> a >> b >> c >> t;
	    C[a-1][b-1] = C[b-1][a-1] = c;
	    T[a-1][b-1] = T[b-1][a-1] = t;
	}
	floyd(m, C, T);
	cin >> k;
	rep(i, k){
	    cin >> a >> b >> q;
	    if ( q ) cout << T[a-1][b-1] << endl;
	    else cout << C[a-1][b-1] << endl;
	}
    }
}

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

struct Node {
    bool isDone;
    int cost;
};

const int MAX_M = 100;
int costTable[MAX_M + 1][MAX_M + 1];
int timeTable[MAX_M + 1][MAX_M + 1];
Node nodes[MAX_M + 1];
int m;

int dijkstra(int start, int end, int r) {
    int (*table)[MAX_M + 1];
    table = (r == 0) ? costTable : timeTable;
    for (int i = 1; i <= m; i++) {
        nodes[i].isDone = false;
        nodes[i].cost = -1;
    }
    nodes[start].cost = 0;
    while (true) {
        int min_idx = -1;
        for (int i = 1; i <= m; i++) {
            if (nodes[i].isDone == true || nodes[i].cost < 0) {
                continue;
            }
            if (min_idx < 0 || nodes[i].cost < nodes[min_idx].cost) {
                min_idx = i;
            }
        }
        if (min_idx < 0) {
            break;
        }
        nodes[min_idx].isDone = true;
        for (int i = 1; i <= m; i++) {
            if (table[min_idx][i] <= 0) {
                continue;
            }
            int cost = nodes[min_idx].cost + table[min_idx][i];
            if (nodes[i].cost < 0 || cost < nodes[i].cost) {
                nodes[i].cost = cost;
            }
        }
    }
    return nodes[end].cost;
}

int main() {
    while (true) {
        int n;
        cin >> n >> m;
        if ((n | m) == 0) {
            break;
        }
        memset(costTable, 0, sizeof(costTable));
        memset(costTable, 0, sizeof(costTable));
        for (int i = 0; i < n; i++) {
            int a, b, cost, time;
            cin >> a >> b >> cost >> time;
            costTable[a][b] = costTable[b][a] = cost;
            timeTable[a][b] = timeTable[b][a] = time;
        }
        int k;
        cin >> k;
        for (int i = 0; i < k; i++) {
            int p, q, r;
            cin >> p >> q >> r;
            cout << dijkstra(p, q, r) << endl;
        }
    }
}

C++: #include <stdio.h>
#include <iostream>
#include <vector>
#include <queue>
#include <functional>

using namespace std;

//FILE* in = freopen("./B","r",stdin);

typedef long long LL;
#define REP(i,a,b)for(LL i=(LL)a;i<(LL)b;i++)


#define MAX_V 3100
#define INF 1000000

struct edge{int to,cost,time;edge(int t,int c,int h):to(t),cost(c),time(h){}};
typedef pair<int, int> P;

int V=MAX_V;
vector<edge> G[MAX_V];
int d[MAX_V];

int dijkstra(int s,int g,bool flag){
	priority_queue<P, vector<P>, greater<P> > que;
	fill(d, d+V, INF);
	d[s] = 0;
	que.push(P(0,s));

	while(!que.empty()){
		P p=que.top(); que.pop();
		int v = p.second;
		if(v==g)return d[v];
		if( d[v] < p.first ) continue;
		for(int i = 0;i<G[v].size();i++){
			edge e = G[v][i];
			if(flag==0){
			if(d[e.to] > d[v] + e.cost ){
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to],e.to));
			}
			}else{
				if(d[e.to] > d[v] + e.time ){
				d[e.to] = d[v] + e.time;
				que.push(P(d[e.to],e.to));
			}

			}
		}
	}
	return -1;
}

int main(void){

	while(1){

		int N,M;
		int cost,time,a,b;
		int K,start,goal,R;

		cin >> N>>M;

		if(!N&&!M)break;

		REP(i,0,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,0,K){
			cin >> start>>goal>>R;
			cout << dijkstra(start,goal,R)<<endl;
		}

	}

	return 0;
}

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

class S{
public:
	S(int pos,int cost){
		p=pos;
		c=cost;
	}
	int p,c;
};
bool operator<(S a,S b){
	return a.c>b.c;
}
int m;
vector<S> edge[100][2];
void add_edge(int a,int b,int c,int t){
	edge[a][0].push_back(S(b,c));
	edge[a][1].push_back(S(b,t));
	edge[b][0].push_back(S(a,c));
	edge[b][1].push_back(S(a,t));
}


int solve(int p,int q,int r){
	int ans=0;
	bool use[100];
	for(int i=0;i<100;i++){
		use[i]=0;
	}
	
	priority_queue<S> que;
	que.push(S(p,0));
	
	while(!que.empty()){
		S n=que.top();que.pop();
		
		if(n.p==q){
			ans=n.c;
			break;
		}
		
		if(use[n.p]){
			continue;
		}
		use[n.p]=1;
		
		
		for(int i=0;i<edge[n.p][r].size();i++){
			if(!use[edge[n.p][r][i].p]){
				que.push(S(edge[n.p][r][i].p,n.c+edge[n.p][r][i].c));
			}
		}
	}
	return ans;
}



int main(){
	int n;
	while(cin>>n>>m,n!=0||m!=0){
		for(int i=0;i<n;i++){
			int a,b,c,t;
			cin>>a>>b>>c>>t;
			a--;b--;
			add_edge(a,b,c,t);
		}
		int k;
		cin>>k;
		for(int i=0;i<k;i++){
			int p,q,r;
			cin>>p>>q>>r;
			p--;q--;
			cout<<solve(p,q,r)<<endl;
		}
	}
}