Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

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
					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 <stdio.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <limits.h>
#include <cctype>

#include <iostream>
#include <vector>
#include <deque>
#include <queue>
#include <map>
#include <algorithm>


using namespace std;

#define Max INT_MAX
#define Inf INT_MIN


#define rep(i, n) for(int i = 0; i < n; i++)
#define repi(i,l,n) for(int (i)=(int)(l);(i)<(int)(n);(i)++)
// s <= x < g ?
#define IN(x,s,g) ((x) >= (s) && (x) < (g))
// 0 <= x < w && 0 <= y < h ?
#define ISIN(x,y,w,h) (IN((x),0,(w)) && IN((y),0,(h)))



struct edge {
    int to, cost;
    edge(int t, int c){
        to = t;
        cost = c;
    }
};

//first=最短距離 second=頂点の番号
typedef pair<int, int> P;

int d[100];


//sからの最短距離をdに格納する
void dijkstra(int s, vector<edge> *G ){
    //フロンティア頂点集合
    priority_queue<P, vector<P>, greater<P> > que; //小さい順指定
    fill(d, d+100, Max);

    d[s] = 0;
    que.push( P(0,s) ); //s -> sは距離0

    while(!que.empty() ) {
        P p = que.top(); que.pop(); //フロンティアの中から一番小さい辺を取り出す 
        int v = p.second;
        if( d[v] < p.first) continue;

        rep(i, G[v].size() ) {
            edge e = G[v][i]; //v->iのエッジ
            //cout << "i = " << i << endl;
            //cout << "G[v][i].to = " << G[v][i].to<< endl;
            //cout << "G[v][i].cost = " << G[v][i].cost << endl;

            //cout << "v = " << v << endl; 
            //cout << "d[v] = " << d[v] << endl;
            //cout << "e.to = " << e.to << endl;
            //cout << "e.cost = " << e.to << endl;
            //cout << "d[e.to] = " << d[e.to] << endl;
            if( d[e.to] > d[v] + e.cost){
                d[e.to] = d[v] + e.cost;
                que.push( P(d[e.to], e.to) );
            }
        }
    }
}

vector<edge> costs[100];
vector<edge> times[100];

int main()
{
    int tmp = 0;

    int n,m;
    while(cin >> n >> m){
        if( n == 0 && m == 0 ) { break; }
        rep(i,n){
            int a,b, cost_v,time_v;
            cin >> a >> b >> cost_v >> time_v;
            //edge ee = edge(b,cost_v);
            //cout << "ee.to = "  << ee.to << endl; 
            //cout << "ee.cost = " << ee.cost << endl;
            costs[a-1].push_back( edge(b-1, cost_v) );
            costs[b-1].push_back( edge(a-1, cost_v) );

            times[a-1].push_back( edge(b-1, time_v) );
            times[b-1].push_back( edge(a-1, time_v) );

            //cout << "_cost = " << cost_v << endl;
            //cout << "_time = " << time_v << endl;
            //cout << "a,b = " << a << " " << b << endl;
            //cout << endl;
        }

        int k;
        cin >> k;

        rep(i,k){
            int p,q,r;
            cin >> p >> q >> r;
            if( r == 0){
                dijkstra(p-1, costs);
            } else {
                dijkstra(p-1, times);
            }
            cout << d[q-1] << endl;
        }
    }
    return 0;


}

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

using namespace std;

#define loop(i,a,b) for(int i=(a); i<(int)(b); i++)
#define rep(i,b) loop(i,0,b)

struct edge{
    int to,money,time;
};
struct state{
    int v,d;
    bool operator<(const state& rhs)const{
        return d>rhs.d;
    }
};

priority_queue<state> q;
vector<vector<edge>> G;
int d[101];

int main(){
    int n,m;
    while(cin>>n>>m,n|m){
        G.resize(m+1);
        rep(i,n){
            int f,t,m,ti; cin>>f>>t>>m>>ti;
            G[f].push_back({t,m,ti});
            G[t].push_back({f,m,ti});
        }
        int k; cin>>k;
        rep(i,k){
            int a,b,c; cin>>a>>b>>c;
            priority_queue<state>().swap(q);
            for(int& i:d) i=1<<30;
            d[a]=0;
            q.push({a,0});
            while(q.size()){
                state sta=q.top(); q.pop();
                if(d[sta.v]<sta.d) continue;
                for(edge& e:G[sta.v]){
                    int cost=(c==0 ? e.money : e.time);
                    if(d[e.to]>d[sta.v]+cost){
                        d[e.to]=d[sta.v]+cost;
                        q.push({e.to,d[e.to]});
                    }
                }
            }
            cout<<d[b]<<endl;
        }
    }
}