Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

const INF = 0x7FFFFFFF

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
				} else {
					c_dist[i][j] = c_matrix[i][j]
				}
				if c_matrix[i][j] == 0{
					c_prev[i][j] = -1
				} else {
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0{
					t_dist[i][j] = INF
				} else {
					t_dist[i][j] = t_matrix[i][j]
				}
				if t_matrix[i][j] == 0{
					t_prev[i][j] = -1
				} else {
					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 <algorithm>
#include <utility>

using namespace std;

int kInf = 1 << 20;
int dtime[101][101];
int dcost[101][101];

int n, m;

void wf() {
	for(int k = 1; k <= m; k++)
		for(int i = 1; i <= m; i++)
			for (int j = 1; j <= m; j++) {
				dtime[i][j] = min(dtime[i][j], dtime[i][k] + dtime[k][j]);
				dcost[i][j] = min(dcost[i][j], dcost[i][k] + dcost[k][j]);
			}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	while (cin >> n >> m, n || m) {
		fill(dtime[0], dtime[101], kInf);
		fill(dcost[0], dcost[101], kInf);
		for (int i = 0; i < 101; i++)
			dtime[i][i] = dcost[i][i] = 0;
		for (int i = 0; i < n; i++) {
			int a, b, cost, time;
			cin >> a >> b >> cost >> time;
			dtime[a][b] = dtime[b][a] = time;
			dcost[a][b] = dcost[b][a] = cost;
		}
		wf();
		int k;
		cin >> k;
		for (int i = 0; i < k; i++) {
			int p, q, r;
			cin >> p >> q >> r;
			if(r)
				cout << dtime[p][q] << endl;
			else
				cout << dcost[p][q] << endl;
		}
	}
}

C++: #include <iostream>
using namespace std;

int min_route(int matrix[101][101], int n, int a, int b)
{
  int cost[101];
  bool done[101];
  const int MAX = 999999999;

  for (int i=1; i<=n; i++)
  {
    cost[i] = MAX;
    done[i] = false;
  }

  cost[a] = 0;
  while (1)
  {
    int mincost = MAX;
    int min_s;
    for (int i=1; i<=n; i++)
    {
      if ((!done[i]) && (mincost > cost[i]))
      {
        min_s = i;
        mincost = cost[i];
      }
    }
    if (min_s == b) return cost[b];
    for (int i=1; i<=n; i++)
    {
      if ((matrix[min_s][i] > 0) && (cost[i] > mincost + matrix[min_s][i]))
      {
        cost[i] = mincost+matrix[min_s][i];
      }
    }
    done[min_s] = true;
  }
}


int main()
{
  int time[101][101];
  int cost[101][101];
  int n, m;                     // n: ?????±?????°, m: ?§??????°
  int a, b, c, t;

  cin >> n >> m;

  for (int i=1; i<=m; i++)
    for (int j=1; j<=m; j++) { time[i][j] = 0; cost[i][j] = 0; }

  for (int i=0; i<n; i++)
  {
    cin >> a >> b >> c >> t;
    time[a][b] = t;
    time[b][a] = t;
    cost[a][b] = c;
    cost[b][a] = c;
  }

  int k;                        // ?????¨????????°
  int p, q, r;                  // r=0:????°??????? 1:????????????
  cin >> k;
  for (int i=1; i<=k; i++)
  {
    cin >> p >> q >> r;
    if (r==0)
    {
      cout << min_route(cost, m, p, q) << endl;
    }
    else
    {
      cout << min_route(time, m, p, q) << endl;
    }
  }
  return 0;
}