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

C++: #include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
class home {
public:
	int time;
	int cost;
	home() :time(-1), cost(-1) {}
};

int main() {
	int n, m;
	while (cin >> n >> m&&n != 0) {
		vector<vector<home> > map(m + 1, vector<home>(m + 1));
		for (int i = 0; i < n; ++i) {
			int a, b, c, d;
			cin >> a >> b >> c >> d;
			map[a][b].cost = c;
			map[b][a].cost = c;
			map[a][b].time = d;
			map[b][a].time = d;
		}
		bool flag = true;
		while (flag) {
			flag = false;
			for (int i = 1; i <= m - 1; ++i) {
				for (int j = i + 1; j <= m; ++j) {
					for (int k = 1; k <= m; ++k) {
						if (i == k || j == k)continue;
						if (map[i][k].cost == -1 || map[j][k].cost == -1)continue;
						if (map[i][k].time == -1 || map[j][k].time == -1)continue;
						int cost = map[i][k].cost + map[j][k].cost;
						int time = map[i][k].time + map[j][k].time;
						if (map[i][j].cost == -1 || map[i][j].cost > cost) {
							flag = true;
							map[j][i].cost = map[i][j].cost = cost;
						}
						if (map[i][j].time == -1 || map[i][j].time > time) {
							flag = true;
							map[i][j].time = map[j][i].time = time;
						}
					}
				}
			}
		}
		int num;
		cin >> num;
		for (int i = 0; i < num; ++i) {
			int a, b, c;
			cin >> a >> b >> c;
			if (c == 0) {
				cout << map[a][b].cost << endl;
			}
			else {
				cout << map[a][b].time << endl;
			}
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <climits> 
#include <map>
using namespace std;

const int MAX_V = 1000; 
const int INF = 100000; 
int v; 
int g[MAX_V][MAX_V]; 
int g2[MAX_V][MAX_V];
int d[MAX_V]; 
bool used[MAX_V]; 

void dijkstra(int s)
{
  fill(d, d + v, INF);
  fill(used, used + v, false);

  

  d[s] = 0;
  for(;;){
    
    int i = -1;
    for(int j = 0; j < v; ++j)
      if(!used[j] && (i == -1 || d[i] > d[j]))
	i = j;
    if(i == -1)break; 
    used[i] = true;
    for(int j = 0; j < v; ++j)
      d[j] = min(d[j], d[i] + g[i][j]);
  }
}

void dijkstra2(int s)
{
  fill(d, d + v, INF);
  fill(used, used + v, false);
  d[s] = 0;
  for(;;){
    int i = -1;
    for(int j = 0; j < v; ++j)
      if(!used[j] && (i == -1 || d[i] > d[j]))
	i = j;
    if(i == -1)break; 
    used[i] = true;
    for(int j = 0; j < v; ++j)
      d[j] = min(d[j], d[i] + g2[i][j]);
  }
}


int main()
{
  for(;;){
    int gv, ge;
    cin >> ge >> gv;
    if(ge==0){return 0;}

    fill(&g[0][0], &g[MAX_V][0], 100000);
    fill(&g2[0][0], &g2[MAX_V][0], 100000);


    for(int i = 0; i < ge; ++i){
      int gs, gt, gd,gd2;
      cin >> gs >> gt >> gd >> gd2;
      g[gs-1][gt-1]=gd;
      g[gt-1][gs-1]=gd;
      g2[gs-1][gt-1]=gd2;
      g2[gs-1][gt-1]=gd2;
    }
    v = gv;

    //for(int i=0;i<v;i++){for(int j=0;j<v;j++){cout << g[i][j] << " ";}cout << endl;}
    
    int k;
    cin >> k;
    for(int i=0;i<k;i++){
      int p,q,r;
      cin >> p >> q >> r;
      if(r==0){
	dijkstra(p-1);
	//for(int j=1;j<=gv;j++)
	  cout << d[q-1] << endl;
      }else{
	dijkstra2(p-1);
	//for(int j=0;j<=gv;j++)
	  cout << d[q-1] << endl;
      }
    }
  }
  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
int main(){
  int n,m;
  while(cin >>n>>m,n||m){
    int c_t[100][100][2],ans[100][100][2];
    for(int i=0; i<100; i++){
      for(int j=0; j<100; j++){
	for(int k=0; k<2; k++){
	  ans[i][j][k] = 100000000;
	  if(i==j) ans[i][j][k] = 0;
	}
      }
    }
    for(int i=0,a,b,c,d; i<n; i++){
      cin >>a>>b>>c>>d;
      a--;b--;
      ans[a][b][0] = ans[b][a][0] = c;
      ans[a][b][1] = ans[a][b][1] = d;
    }
    for(int k=0; k<2; k++){
      for(int i=0; i<m; i++){
	for(int j=0; j<m; j++){
	  for(int l=0; l<m; l++){
	    ans[i][j][k] = min(ans[i][j][k],ans[i][l][k]+ans[l][j][k]);
	  }
	}
      }
    }
    int t=0;
    cin >>t;
    while(t--){
      int p,q,r;
      cin >>p>>q>>r;
      cout <<ans[p-1][q-1][r]<<endl;
    }
  }
  return 0;
}