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 <cctype>
#include <algorithm>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <utility>
#include <string>
#include <functional>
#include <cctype>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
typedef long long ll;
const int INF = 100000000, mod = 1000000007;
const ll LLINF = 1LL << 50;
using namespace std;

struct edge { int to, cos, tim; };
typedef pair<int, int> P;
vector<edge> G[105];
int n, m, k, cost[105], time[105];

void dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> costque, timeque;
    fill(cost, cost + m + 1, INF);
    fill(time, time + m + 1, INF);
    cost[s] = 0;
    time[s] = 0;
    costque.push(P(s, 0));
    timeque.push(P(s, 0));

    while (!costque.empty()) {
        P p = costque.top();
        costque.pop();
        int v = p.first;
        if (cost[v] < p.second) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (cost[e.to] > cost[v] + e.cos) {
                cost[e.to] = cost[v] + e.cos;
                costque.push(P(e.to, cost[e.to]));
            }
        }
    }
    while (!timeque.empty()) {
        P p = timeque.top();
        timeque.pop();
        int v = p.first;
        if (time[v] < p.second) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (time[e.to] > time[v] + e.tim) {
                time[e.to] = time[v] + e.tim;
                timeque.push(P(e.to, time[e.to]));
            }
        }
    }
}

int main() {
    while (1) {
        cin >> n >> m;
        if (n == 0&&m == 0) break;
        for (int i = 0; i < n; i++) {
            int a, b, c, t;
            cin >> a >> b >> c >> t;
            edge tmp = { b,c,t };
            G[a].push_back(tmp);
        }
        cin >> k;
        for (int i = 0; i < k; i++) {
            int p, q, r;
            cin >> p >> q >> r;
            dijkstra(p);
            if (r == 0) cout << cost[q] << endl;
            else cout << time[q] << endl;
        }
    }
    return 0;
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <utility>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <map>
#include <set>
#include <stack>
#include <queue>
 
using namespace std;
 
#define pb(n)	push_back(n)
#define mp(n,m) make_pair(n,m)
#define fi 	first
#define se 	second
#define all(r) (r).begin(),(r).end()
 
#define REP(i,s,e)	for(ll i=(s); i<(e); i++)
#define rep(i,n)	REP(i,0,n)
#define REPE(i,s,e)	for(ll i=s; i>e; i--)
#define repe(i,n)	REPE(i,n,-1)
 
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
 
typedef vector<vi> vvi;
 
const int IMAX=((1<<30)-1)*2+1;
const int INF=100000000;
const double EPS=1e-10;
//int mod=1000000007


const int MAX_V = 200;

int d[MAX_V][MAX_V];
int e[MAX_V][MAX_V];
int V;
 
void warshall_floyd_init(){
	for(int i = 0; i < V; i++){
		for(int j = 0; j < V; j++){
			if(i == j) d[i][i] = e[i][i] = 0;
			else d[i][j] = e[i][j] = INF;
		}
	}
}

void warshall_floyd() {
	for (int k = 0; k < V; k++) {
		for (int i = 0; i < V; i++) {
			for (int j = 0; j < V; j++) {
				d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
				e[i][j] = min(e[i][j], e[i][k] + e[k][j]);
			}
		}
	}
}

int main(){
	int n,m;
	while(cin>>n>>m){
		if(n == 0 && m == 0) break;
		V = m;
		int a,b,cost,time;
		warshall_floyd_init();
		rep(i, n) {
			cin>>a>>b>>cost>>time;
			a--; b--;
			d[a][b] = d[b][a] = cost;
			e[a][b] = e[b][a] = time;
		}
		warshall_floyd();
		int k, c;
		cin>>k;
		for(int i = 0; i < k; i++){
			cin>>a>>b>>c;
			a--; b--;
			if(c == 0) cout<<d[a][b]<<endl;
			else cout<<e[a][b]<<endl;
		}
	}
	
}

C++: #include<iostream>
#include<algorithm>
const int INF = 1<<20;
const int N = 101;
int cost[N][N];
int tim[N][N];
using namespace std;
int main()
{
	cout << INF << endl;
	int n, m, a, b, co, ti,r;
	while (1){
		cin >> n >> m;
		if (n == 0 && m == 0)return 0;
		for (int i = 0; i < N; i++){
			for (int i2 = 0; i2 < N; i2++){
				cost[i][i2] = INF;
				tim[i][i2] = INF;
			}
		}
		for (int i = 0; i < n; i++){
			cin >> a >> b >> co >> ti;
			cost[a][b] = co;
			cost[b][a] = co;
			tim[a][b] = ti;
			tim[b][a] = ti;
		}
		for (int k = 0; k < m+1; ++k)
			for (int i = 0; i < m+1; ++i)
				for (int j = 0; j < m+1; ++j)
				{
					cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
					tim[i][j] = min(tim[i][j], tim[i][k] + tim[k][j]);
				}
		cin >> m;
		for (int i = 0; i < m; i++){
			cin >> a >> b >> r;
			if (r == 0){
				cout << cost[a][b] << endl;
			}
			else
				cout << tim[a][b] << endl;
		}
	}
}