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>
#include <queue>

using namespace std;

int main(void) {
	int n,m,k,p,q,r;
	while (cin >> n >> m && n && m) {
		int dp[101][101][2];
		for (int i = 0; i < m + 1; ++i) {
			for (int j = 0; j < m + 1; ++j) {
				for (int k = 0; k < 2; ++k) {
					if (i == j) {
						dp[i][j][k] = 0;
					}
					else {
						dp[i][j][k] = 1001;
					}
				}
			}
		}

		int a,b,c,t;
		for (int i = 0; i < n; ++i) {
			cin >> a >> b >> dp[a][b][0] >> dp[a][b][1];
			dp[b][a][0] = dp[a][b][0];
			dp[b][a][1] = dp[a][b][1];
		}

		for (int mode = 0; mode < 2; ++mode) {
			for (int k = 1; k < m + 1; ++k) {
				for (int i = 1; i < m + 1; ++i) {
					for (int j = 1; j < m + 1; ++j) {
						dp[i][j][mode] = min(dp[i][j][mode], dp[i][k][mode]+dp[k][j][mode]);
					}
				}
			}
		}

		cin >> k;
		for (int i = 0; i < k; ++i) {
			cin >> p >> q >> r;
			cout << dp[p][q][r] << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <map>
#define INF (int)1e9


int common_part(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > v); 
void bellman_ford(int m, std::vector<std::vector<std::pair<int, int> > > &v, std::vector<int> &rvec); 
void dijkstra(int m, int p, std::vector<std::vector<std::pair<int, int> > > &v, std::vector<int> &rvec); 


int main(void) {
    int n;
    int m;

    int a;
    int b;
    int cost;
    int time;

    int k;

    int p;
    int q;
    int r;

    int res;

    while (true) {
        std::cin >> n >> m;
        if (n == 0 && m == 0) {
            break; 
        }

        std::vector<std::vector<std::pair<int, int> > > vcost(m);
        std::vector<std::vector<std::pair<int, int> > > vtime(m);

        for (int i = 0; i < n; i++) {
            std::cin >> a >> b >> cost >> time;
            --a;
            --b;
            vcost[a].push_back(std::make_pair(cost, b));
            vcost[b].push_back(std::make_pair(cost, a));
            vtime[a].push_back(std::make_pair(time, b));
            vtime[b].push_back(std::make_pair(time, a));
        }

        std::cin >> k;

        for (int i = 0; i < k; i++) {
            std::cin >> p >> q >> r;
            --p;
            --q;

            // Bellman Ford or Dijkstra
            if (r == 0) {
                res = common_part(m, p, q, vcost);
            } else {
                res = common_part(m, p, q, vtime);
            }
            std::cout << res << std::endl;
        }
    }
    return 0;
}

void bellman_ford(int m, std::vector<std::vector<std::pair<int, int> > > &v, std::vector<int> &rvec) {
    int value;
    int target;
    bool flag;

    do{
        flag = false;

        for (int i = 0; i < m; i++) {
            for (int j = 0; j < v[i].size(); j++) {
                value = v[i][j].first;
                target = v[i][j].second;
                if (rvec[target] > rvec[i] + value) {
                    rvec[target] = rvec[i] + value;
                    flag = true;
                }
            }
        }

    } while(flag);

    return;
} 

void dijkstra(int m, int p, std::vector<std::vector<std::pair<int, int> > > &v, std::vector<int> &rvec) {
    std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int> >, std::greater<std::pair<int, int> > > pq;
    std::vector<int> search_count(m, 0);
    int start_value;
    int start_target;
    int end_value;
    int end_target;
    pq.push(std::make_pair(rvec[p], p));

    while(true) {
        if (pq.empty() == 1) {
           break; 
        }
        start_value = pq.top().first; 
        start_target = pq.top().second;
        pq.pop();
        if (search_count[start_target] == 0) {
            ++search_count[start_target];
            for (int i = 0; i < v[start_target].size(); i++) {
                end_value = v[start_target][i].first;
                end_target = v[start_target][i].second;
                if (rvec[end_target] > end_value + rvec[start_target]) {
                    rvec[end_target] = end_value + rvec[start_target];
                }
                pq.push(std::make_pair(rvec[end_target], end_target));
            }
        }
    }

    return;
} 

int common_part(int m, int p, int q, std::vector<std::vector<std::pair<int, int> > > v) {
    std::vector<int> rvec(m, INF);
    rvec[p] = 0;

    //bellman_ford(m, v, rvec);
    dijkstra(m, p,  v, rvec);

    return rvec[q];
}