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 <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
typedef pair<ll, P> P3;
typedef pair<P ,P> PP;
constexpr ll MOD = ll(1e9+7);
constexpr int IINF = INT_MAX;
constexpr ll LLINF = LLONG_MAX;

int main() {
    int n, m, c[100][100], t[100][100];
    while(cin >> m >> n, n){
        for(int i=0;i<n;i++){
            fill(c[i],c[i]+n,IINF/3);
            fill(t[i],t[i]+n,IINF/3);
        }
        for(int i=0;i<m;i++){
            int a, b;
            cin >> a >> b;
            a--; b--;
            cin >> c[a][b] >> t[a][b];
            c[b][a] = c[a][b];
            t[b][a] = t[a][b];
        }
        for(int k=0;k<n;k++){
            for(int i=0;i<n;i++){
                for(int j=0;j<n;j++){
                    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]);
                }
            }
        }
        int q;
        cin >> q;
        for(int i=0;i<q;i++){
            int a, b, r;
            cin >> a >> b >> r;
            a--; b--;
            cout << (r ? t[a][b] : c[a][b]) << endl;
        }
    }
    return 0;
}

C++: // 2014/06/16 Tazoe

#include <iostream>
using namespace std;

const int INF = 1000000000;

int main()
{
	while(true){
		int n, m;
		cin >> n >> m;

		if(n==0 && m==0)
			break;

		int C[100][100];
		int T[100][100];
		for(int i=0; i<m; i++){
			for(int j=0; j<m; j++){
				if(i==j){
					C[i][j] = T[i][j] = 0;
				}
				else{
					C[i][j] = T[i][j] = INF;
				}
			}
		}

		for(int i=0; i<n; i++){
			int a, b, c, t;
			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;
		}
    for(int i=0;i<n;i++){
      for(int j=0;j<n;j++){
        for(int k=0;k<n;k++){
          if(C[i][j] > C[i][k]+C[k][j])
            C[i][j] = C[i][k] + C[k][j];
          if(T[i][j] > T[i][k]+T[k][j])
            T[i][j] = T[i][k] + T[k][j];
        }
      }
    }
    unsigned int k;
    cin >> k;
    for(int i=0;i<k;i++){
      int p,q,r;
      cin >> p >> q;
      if(k == 0  &&  q == 0)
        return 0;
      cin >> r;

      if(r==0){
        cout << C[p][q] << endl;
      } else {
        cout << T[p][q] << endl;
      }
    }

	}

	return 0;
}

C++: #include<cstdio>
#include<vector>
#include<queue>
using namespace std;
int main(){
    for(;;){
        int n,m;
        scanf("%d%d",&n,&m);
        if(n==0&&m==0)break;
        vector<vector<int> > costs(m,vector<int>(m,-1));
        vector<vector<int> > times(m,vector<int>(m,-1));
        for(int i=0;i<n;i++){
            int a,b,cost,time;
            scanf("%d%d%d%d",&a,&b,&cost,&time);
            a--;b--;
            costs[a][b]=cost;
            costs[b][a]=cost;
            times[a][b]=time;
            times[b][a]=time;
        }
        int k;
        scanf("%d",&k);
        for(int i=0;i<k;i++){
            int p,q,r;
            scanf("%d%d%d",&p,&q,&r);
            p--;q--;
            if(r==1){
                vector<int> d(m,-1);
                d[p]=0;
                priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > lens;
                lens.push(make_pair(0,p));
                while(!lens.empty()){
                    pair<int,int> p = lens.top();
                    lens.pop();
                    int v=p.second;
                    if(d[v]<p.first)continue;
                    for(int j=0;j<m;j++){
                        if(times[v][j]!=-1&&(d[j]>d[v]+times[v][j]||d[j]==-1)){
                            d[j]=d[v]+times[v][j];
                            lens.push(make_pair(d[j],j));
                        }
                    }
                }
                printf("%d\n",d[q]);
            }else{
                vector<int> d(m,-1);
                d[p]=0;
                priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > lens;
                lens.push(make_pair(0,p));
                while(!lens.empty()){
                    pair<int,int> p = lens.top();
                    lens.pop();
                    int v=p.second;
                    if(d[v]<p.first)continue;
                    for(int j=0;j<m;j++){
                        if(costs[v][j]!=-1&&(d[j]>d[v]+costs[v][j]||d[j]==-1)){
                            d[j]=d[v]+costs[v][j];
                            lens.push(make_pair(d[j],j));
                        }
                    }
                }
                printf("%d\n",d[q]);
            }
        }
    }
}