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>
using namespace std;

int main(){
  while(true){
    int n,m;
    cin >> n >> m;
    if(n==0 && m==0){
      break;
    }

    int INF=1000000000;
    int way_co[m][m];
    int way_ti[m][m];
    for(int i=0; i<m; i++){
      for(int j=0; j<m; j++){
        way_co[i][j] = INF;
        way_ti[i][j] = INF;
        if(i==j){
          way_co[i][j] = 0;
          way_ti[i][j] = 0;
        }
      }
    }

    int a,b,cost,tim;
    for(int i=0; i<n; i++){
      cin >> a >> b >> cost >> tim;
      way_co[a-1][b-1] = cost;
      way_ti[a-1][b-1] = tim;
    }

    int d_co[m][m];
    int d_ti[m][m];
    for(int i=0; i<m; i++){
      for(int j=0; j<m; j++){
        d_co[i][j] = way_co[i][j];
        d_ti[i][j] = way_ti[i][j];
      }
    }

    for(int k=0; k<m; k++){
      for(int i=0; i<m; i++){
        for(int j=0; j<m; j++){
          if(d_co[i][j] > d_co[i][k] + d_co[k][j]){
            d_co[i][j] = d_co[i][k] + d_co[k][j];
          }
          if(d_ti[i][j] > d_ti[i][k] + d_ti[k][j]){
            d_ti[i][j] = d_ti[i][k] + d_ti[k][j];
          }
        }
      }
    }
    int y;
    cin >> y;
    for(int i=0; i<y; i++){
      int a,b,c;
      cin >> a >> b >> c;
      if(c==0){
        cout << d_co[a-1][b-1] << endl;
      }else{
        cout << d_ti[a-1][b-1] << endl;
      }
    }
  }
  return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <vector>
#include <list>
#include <cmath>
#include <fstream>
#include <algorithm>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <complex>
#include <iterator>
#include <cstdlib>
#include <sstream>

using namespace std;

#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) (EQ((a).real(),(b).real()) && EQ((a).imag(),(b).imag()))

typedef long long ll;

const int MAX_SIZE = 10000;

struct edge{
	int to;
	int cost;
};

typedef pair<int,int> P;
int V;

const int MAX_V = 5000;

vector<edge> G[MAX_V];
vector<edge> G2[MAX_V];
int d[MAX_V];
const int INF = 100000000;

int prevv[MAX_V];

void dijkstra(int s){
  priority_queue<P,vector<P>,greater<P> > que;
  fill(d,d+MAX_V,INF);
  fill(prevv,prevv+MAX_V,-1);
  d[s] = 0;
  que.push(P(0,s));
  while(!que.empty()){
    P p = que.top();
    que.pop();
    int v = p.second;
    if(d[v] < p.first)
      continue;
    for(int i = 0; i < G[v].size(); i++){
      edge e = G[v][i];
      if(d[e.to] > d[v] + e.cost){
	d[e.to] = d[v] + e.cost;
	que.push(P(d[e.to],e.to));
	// ツつサツづ個ノツーツドツづ鳴づ個催短ツ仰猟猟」ツ経ツ路ツづーツ記ツ録ツつオツづつィツつュ
	prevv[e.to] = v;
      }
    }
  }
}
void dijkstra2(int s){
  priority_queue<P,vector<P>,greater<P> > que;
  fill(d,d+MAX_V,INF);
  fill(prevv,prevv+MAX_V,-1);
  d[s] = 0;
  que.push(P(0,s));
  while(!que.empty()){
    P p = que.top();
    que.pop();
    int v = p.second;
    if(d[v] < p.first)
      continue;
    for(int i = 0; i < G2[v].size(); i++){
      edge e = G2[v][i];
      if(d[e.to] > d[v] + e.cost){
	d[e.to] = d[v] + e.cost;
	que.push(P(d[e.to],e.to));
	// ツつサツづ個ノツーツドツづ鳴づ個催短ツ仰猟猟」ツ経ツ路ツづーツ記ツ録ツつオツづつィツつュ
	prevv[e.to] = v;
      }
    }
  }
}

int main(){

	int n,m;
	while(cin>>n>>m&&!(n==0&&m==0)){
		for(int i = 0; i < n; i++){
			int from,to,money,time;
			cin>>from>>to>>money>>time;
			edge e;
			e.to=to;
			e.cost=money;
			G[from].push_back(e);
			e.to=from;
			G[to].push_back(e);

			e.cost=time;
			G2[to].push_back(e);
			e.to=to;
			G2[from].push_back(e);

		}
		int k;
		cin>>k;
		for(int i = 0; i < k; i++){
			int s,g,r;
			cin>>s>>g>>r;
			if(r==0){
				dijkstra(s);
				cout<<d[g]<<endl;
			}
			else{
				dijkstra2(s);
				cout<<d[g]<<endl;
			}
		}
		for(int i = 0; i < MAX_V; i++){
			G[i].clear();
			G2[i].clear();
		}
	}


	return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#include<set>
#include<complex>
#include<map>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<s;i++)
#define CC puts("-------ok--------");
#define all(in) in.begin(), in.end()
using namespace std;
typedef pair<int, int> pii;
#define MAX 99999999
int main(){
	int n,m;
	cin>>n>>m;
	vector<vector<pii>>v(n+1,vector<pii>(n+1,pii(INF,INF)));
	rep(i,n+1)v[i][i]=pii(INF,INF);
	rep(i,n){
		pii temp;
		int s,g;
		cin>>s>>g>>temp.first>>temp.second;
        v[--s][--g]=temp;
	}
	int k; cin>>k;
    rep(u,k){
    int s,g; int r;
    cin>>s>>g>>r;
    if(!r){
        rep(k,m){
            rep(j,m){
                rep(i,m){
                    v[i][j].first=min(v[i][k].first+v[k][j].first,v[i][j].first);
                }
            }
        }
        cout<<v[--s][--g].first<<endl;
    }else{
        rep(k,m){
            rep(j,m){
                rep(i,m){
                    v[i][j].second=min(v[i][k].second+v[k][j].second,v[i][j].second);
                }
            }
        }
        cout<<v[--s][--g].second<<endl;
    }
    }
}