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
			c_matrix[b-1][a-1] = c
			t_matrix[a-1][b-1] = t
			t_matrix[b-1][a-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 <fstream>
#include <typeinfo>
#include <vector>
#include <cmath>
#include <set>
#include <string>
#include <algorithm>
#include <cstdio>
#include <queue>
#include <iomanip>
#include <cctype>
#define syosu(x) fixed<<setprecision(x)
using namespace std;
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
typedef pair<double,double> pdd;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<P> vp;
typedef vector<vp> vvp;
typedef pair<int,P> pip;
typedef vector<pip> vip;
const int inf=1<<25;
const double pi=acos(-1);
const double eps=1e-8;
const vi emp;

class Graph{
	private:
	int V;
	public:
	vvi Pro;
	Graph(int v){
		V=v;
		Pro=vvi(v,vi(v,inf));
		for(int i=0;i<v;i++) Pro[i][i]=0;
	}
	void add_edge(int x,int y,int c){
		Pro[x][y]=c;
		Pro[y][x]=c;
	}
	void Warshall(){
		for(int k=0;k<V;k++){
			for(int i=0;i<V;i++){
				for(int j=0;j<V;j++){
					Pro[i][j]=min(Pro[i][j],Pro[i][k]+Pro[k][j]);
				}
			}
		}
	}
};

int V,E,N;

int main(){
	while(1){
		cin>>E>>V;
		if(!V&&!E) break;
		Graph cost(V),time(V);
		int s,t,c,l;
		for(int i=0;i<E;i++){
			cin>>s>>t>>c>>l;
			s--;
			t--;
			cost.add_edge(s,t,c);
			time.add_edge(s,t,l);
		}
		cost.Warshall();
		time.Warshall();
		cin>>N;
		bool r;
		for(int i=0;i<N;i++){
			cin>>s>>t>>r;
			s--;
			t--;
			if(r) cout<<time.Pro[s][t]<<endl;
			else cout<<cost.Pro[s][t]<<endl;
		}
	}
}

C++: #include <algorithm>
#include <map>
#include <vector>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <cstdlib>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <set>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define IREP(it,array) for(vector<int>::iterator it=array.begin(); it!=array.end(); ++it)
#define SREP(it,array) for(vector<string>::iterator it=array.begin(); it!=array.end(); ++it)

#define MP       make_pair
#define PB       push_back
#define ALL(x)   (x).begin(),(x).end()

const int INF = 1<<29;
const double EPS = 1e-9;
double zero(double d){
  return d < EPS ? 0.0 : d;
}

typedef long long LL;
typedef pair<int,int> P;


int main()
{
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(7);

  int n,m;
  cin >> n >> m;

  vector< vector<int> > cost(m+1, vector<int>(m+1,INF)),
    time(m+1, vector<int>(m+1,INF));

  REP(i,cost.size()){
    cost[i][i] = 0;
    time[i][i] = 0;
  }

  REP(i,n){
    int a,b,c,t;
    cin >> a >> b >> c >> t;
    cost[a][b] = c;
    cost[b][a] = c;
    time[a][b] = t;
    time[b][a] = t;
  }

  int k;
  cin >> k;
  REP(_tmp,k){
    int p,q,r;
    cin >> p >> q >> r;

    vector< vector<int> > data(m+1, vector<int>(m+1,0));
    data = r ? time : cost;

    deque<bool> reached(m+1,0);
    vector<int> dis(m+1,INF);
    dis[p] = 0;

    while(true){
      int minn = -1;
      REP(i,reached.size()){
	if( ! reached[i] ){
	  if( minn==-1 || dis[minn] > dis[i] ){
	    minn = i;
	  }
	}
      }
      if( minn == q )
	break;

      reached[minn] = true;
      REP(i,data[minn].size()+1){
	dis[i] = min( dis[minn] + data[minn][i], dis[i] );
      }
    }

    cout << dis[q] << endl;
  }

  return 0;
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int dp[105][105][2], n, m;

int main(){
    int k;
    int a, b, c, d;
    int st, en, de;

    while(cin >> n >> m, n||m){
        rep(i, 105){
            rep(j, 105){
                rep(k, 2){
                    dp[i][j][k] = 2 << 24;
                }
            }
        }

        rep(i, n){
            cin >> a >> b >> c >> d;
            dp[a][b][0] = dp[b][a][0] = c;
            dp[a][b][1] = dp[b][a][1] = d;
        }

        rep(i, m){
            rep(j, m){
                rep(k, m){
                    dp[i][j][0] = min(dp[i][k][0] + dp[k][j][0], dp[i][j][0]);
                    dp[i][j][1] = min(dp[i][k][1] + dp[k][j][1], dp[i][j][1]);
                }
            }
        }

        cin >> k;
        rep(i, k){
            cin >> st >> en >> de;
            cout << dp[st][en][de] << endl;
        }
    }
}

C++: #include <iostream>

#define N 101
#define INF 1e+9

using namespace std;

int cost[N][N],time[N][N];

int main(void){
	int n,m;
	while(cin>>n>>m,n||m){
		for(int i=0;i<n;++i)for(int j=0;j<n;++j){cost[i][j]=time[i][j]=INF;}
		for(int i=0,a,b,c,t;i<n;++i){
			cin>>a>>b>>c>>t;
			cost[a][b]=cost[b][a]=c;
			time[a][b]=time[b][a]=t;
		}
		int k;cin>>k;
		for(int i=0,p,q,r;i<k;++i){
			cin>>p>>q>>r;
			if(r){//time
				int d[N];
				for(int j=0;j<n;++j) d[j]=INF;
				d[p]=0;
				bool f=false;
				for(;;){
					for(int j=0;j<n;++j){//from
						for(int k=0;k<n;++k){//to
							if(d[j]!=INF && d[j] + time[j][k] < d[k]){
								f==true;
								d[k] = d[j] + time[j][k];
							}
						}
					}
					if(f==false) break;
					f=false;
				}
				cout<<d[q]<<endl;
			}else{//cost
				int d[N];
				for(int j=0;j<n;++j) d[j]=INF;
				d[p]=0;
				bool f=false;
				for(;;){
					for(int j=0;j<n;++j){//from
						for(int k=0;k<n;++k){//to
							if(d[j]!=INF && d[j] + cost[j][k] < d[k]){
								f==true;
								d[k] = d[j] + cost[j][k];
							}
						}
					}
					if(f==false) break;
					f=false;
				}
				cout<<d[q]<<endl;
			}
		}
	}
	return 0;
}