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 <vector>
using namespace std;
#define REP(i,n) for (int i=0; i<(n); ++i)

int main() {
    int n, m;
    while (cin >> n >> m, n || m) {
        int d[2][101][101];
        REP(i,2) REP(j,m+1) REP(k,m+1) {
            d[i][j][k] = (j == k ? 0 : 1e8);
        }
        int a, b, cost, time;
        REP(i,n) {
            cin >> a >> b >> cost >> time;
            d[0][a][b] = min(d[0][a][b], cost);
            d[0][b][a] = min(d[0][b][a], cost);
            d[1][a][b] = min(d[1][a][b], time);
            d[1][b][a] = min(d[1][b][a], time);
        }
        REP(k,m+1) REP(i,m+1) REP(j,m+1) {
            d[0][i][j] = min(d[0][i][j], d[0][i][k] + d[0][k][j]);
            d[0][j][i] = min(d[0][j][i], d[0][j][k] + d[0][k][i]);
            d[1][i][j] = min(d[1][i][j], d[1][i][k] + d[1][k][j]);
            d[1][j][i] = min(d[1][j][i], d[1][j][k] + d[1][k][i]);
        }
        int k, p, q, r;
        cin >> k;
        REP(i,k) {
            cin >> p >> q >> r;
            cout << d[r][p][q] << endl;
        }
    }
    return 0;
}

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

		for(int i=0; i<n; i++){
			int a, b, c, t;
			cin >> a >> b >> c >> t;

			Cost[a-1][b-1] = Cost[b-1][a-1] = c;
			Time[a-1][b-1] = Time[b-1][a-1] = t;
		}
    for(int i =0;i<m;i++){
      for(int j =0;j<m;j++){
        for(int k = 0;k<m;k++){
          if(Cost[j][k]>Cost[j][i]+Cost[i][k]){
            Cost[j][k]=Cost[j][i]+Cost[i][k];
          }
          if(Time[j][k]>Time[j][i]+Time[i][k]){
            Time[j][k]=Time[j][i]+Time[i][k];
          }
        }
      }
    }
    int k;
    cin >>k;
    for(int i =0;i<k;i++){
      int p,q,r;
      cin >>p>>q>>r;
      if(r)cout << Time[p][q]<<endl;
      else cout << Cost[p][q]<<endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<queue>
#include<algorithm>
#include<vector>
using namespace std;
typedef pair<int,int> P;
int D[440];
int n,m,x,y,cost,Time,p,q,r;
vector<P> matrix1[440],matrix2[440];
void djkstra1(int s){ 
    priority_queue<P,vector<P>,greater<P> > que;
    for(int i=0;i<n+2;i++)D[i] = 10000000;
    D[s] = 0;
    que.push(P(s,0));

    while(!que.empty() ){
      P p = que.top();que.pop();
      int v = p.first;
      if(D[v] < p.second)continue;
      for(int i=0;i<matrix1[v].size();i++){
	P pp = matrix1[v][i];
	if(D[pp.first] > D[v] + pp.second){
	  D[pp.first] = D[v] + pp.second;
	  que.push(P(pp.first,D[pp.first]));
	}
      }
    }
}

void djkstra2(int s){ 
    priority_queue<P,vector<P>,greater<P> > que;
    for(int i=0;i<n+2;i++)D[i] = 10000000;
    D[s] = 0;
    que.push(P(s,0));

    while(!que.empty() ){
      P p = que.top();que.pop();
      int v = p.first;
      if(D[v] < p.second)continue;
      for(int i=0;i<matrix2[v].size();i++){
	P pp = matrix2[v][i];
	if(D[pp.first] > D[v] + pp.second){
	  D[pp.first] = D[v] + pp.second;
	  que.push(P(pp.first,D[pp.first]));
	}
      }
    }
}



int main(){

  while(true){
    cin >> n >> m;
    if(n+m == 0)break;
   
    for(int i=0;i<n+2;i++){
      matrix1[i].clear();
      matrix2[i].clear();
    }
    for(int i=0;i<n;i++){
      cin >> x >> y >> cost >> Time;
      matrix1[x].push_back(P(y,cost));
      matrix2[x].push_back(P(y,Time));
      matrix1[y].push_back(P(x,cost));
      matrix2[y].push_back(P(x,Time));
    }


   
   

    int k;
    cin >> k;
    for(int i=0;i<k;i++){
      cin >> p >> q >> r;
      if(r == 0){
	djkstra1(p);
	cout << D[q] << endl;
      }
      else{
	djkstra2(p);
	cout << D[q] << endl;
      }

    }

  }
  return 0;
}