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
			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
					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 <array>
#include <queue>

using namespace std;

int const Inf = 10000000;
int const N = 100;

typedef array<int, 2> line;

struct tg { int c, v; };
bool operator>( tg const& lhs, tg const& rhs )
{
    return lhs.c > rhs.c;
}

int main()
{
    int n, m;
    priority_queue<tg, vector<tg>, greater<tg>> w;

    while( cin >> n >> m, n||m ) {
        line table[N][N] = {};

        for( int i=0; i<n; ++i ) {
            int a, b, cost, time;
            cin >> a >> b >> cost >> time;

            int const from = a-1, to = b-1;
            line const in = {{cost, time}};
            table[from][to] = ( table[to][from] = in );
        }

        int k;
        cin >> k;
        for( int i=0; i<k; ++i ) {
            int p, q, r;
            cin >> p >> q >> r;
            int const from = p-1, to = q-1;

            bool v[N] = {};
            int d[N];
            fill( d, d+N, Inf );

            tg const val = { 0, from };
            w.push( val );
            d[from] = 0;

            while( !w.empty() ) {
                int const cur = w.top().v;
                w.pop();

                if ( v[cur] )
                    continue;
                v[cur] = true;

                for( int ii=0; ii<m; ++ii ) {
                    if ( table[cur][ii][0] == 0 )
                        continue;

                    if ( d[cur] + table[cur][ii][r] < d[ii] ) {
                        d[ii] = d[cur] + table[cur][ii][r];
                        tg const val = { d[cur] + table[cur][ii][r], ii };
                        w.push( val );
                    }

                    //cout << cur+1 << " -> " << ii+1 << " c " << d[ii] << endl;
                }
                

            }

            cout << d[to] << endl;
        }
    }
}

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

using namespace std;

struct Edge{
    int from,to,cost;
    Edge(int from,int to,int cost)
        : from(from),to(to),cost(cost) {};
};

const int INF = 1 << 30;
// s:始点,dist:距離,prev:最短経路木
bool bellman(const vector<vector<Edge> >& graph,int s,vector<int> &dist,vector<int> &prev){
    int n = graph.size();
    for(int i=0;i<n;i++) dist[i] = INF;
    dist[s] = 0;
    for(int i=0;i<n;i++) prev[i] = -1;

    bool neg_cycle = false;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            for(int k=0;k<graph[j].size();k++){
                Edge e = graph[j][k];
                if(dist[e.to] > dist[e.from] + e.cost){
                    dist[e.to] = dist[e.from] + e.cost;
                    prev[e.to] = e.from;
                    if(i == n-1){
                        dist[e.to] = -INF;
                        neg_cycle = true;
                    }
                }
            }
        }
    }
    return !neg_cycle;
}

int main(){
    while(true){
        int n,m;
        cin >> n >> m;
        if(n == 0 and m == 0) break;
        vector<vector<Edge> > C(m);
        vector<vector<Edge> > T(m);

        for(int i=0;i<n;i++){
            int a,b,cost,time;
            cin >> a >> b >> cost >> time;
            a--;b--;
            C[a].push_back(Edge(a,b,cost));
            C[b].push_back(Edge(b,a,cost));
            T[a].push_back(Edge(a,b,time));
            T[b].push_back(Edge(b,a,time));
        }
        int k;
        cin >> k;
        for(int i=0;i<k;i++){
            int p,q,r;
            cin >> p >> q >> r;
            p--,q--;
            vector<int> dist(m);
            vector<int> prev(m);
            if(r == 0){
                bellman(C,p,dist,prev);
            }else{
                bellman(T,p,dist,prev);
            }
            cout << dist[q] << endl;
        }
    }
    return 0;
}

C++: #include<iostream>

#define INF 1000000

int list[101][101][2];
int cost[101];
bool used[101];
int n,m,k;

int main(){
	while(std::cin>>n>>m){
		if(n==0&&m==0)break;
		for(int i=0;i<=m;i++){
			for(int j=0;j<=m;j++){
				list[i][j][0]=INF;
				list[i][j][1]=INF;
			}
		}
		for(int i=0;i<n;i++){
			int a,b,c,d;
			std::cin>>a>>b>>c>>d;
			list[a][b][0]=c;list[a][b][1]=d;
			list[b][a][0]=c;list[b][a][1]=d;
		}
		std::cin>>k;
		for(int i=0;i<k;i++){
			for(int j=0;j<=m;j++)cost[j]=INF,used[j]=false;
			int p,q,r;
			std::cin>>p>>q>>r;
			cost[p]=0;
			while(1){
				used[p]=true;
				if(used[q])break;
				for(int i=1;i<=m;i++){
					if(list[p][i][r]!=INF){
						if(cost[i]>cost[p]+list[p][i][r])cost[i]=cost[p]+list[p][i][r];
					}
				}
				p=0;
				for(int i=1;i<=m;i++){
					if(!used[i]&&cost[p]>cost[i])p=i;
				}
			}
			std::cout<<cost[q]<<std::endl;
		}
	}
	return 0;
}