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>
const int MAX_E = 300, MAX_V = 100, INF = 1000000;
struct edge{int from, to, time, cost;};

edge es[MAX_E];
int d[MAX_V+1];
int n, m, k;

//0: time 1: cost
int minimum_value(int type, int start, int end){
	for(int i=0;i<MAX_V+1;i++)d[i] = INF;
	d[start] = 0;

	int res = 0;
	while(true){
		bool update = false;
		for(int i=0;i<n;i++){
			edge e = es[i];
			int cost = type?e.cost:e.time;
			if(d[e.from] != INF && d[e.to] > d[e.from] + cost){
				d[e.to] = d[e.from] + cost;
				res = d[e.to];
				update = true;
			}		
		}
		if(!update)break;
	}

	return res;
}

int main(){
	while(std::cin >> n >> m, n){
		for(int i=0;i<n;i++){
			int from, to, time, cost;
			std::cin >> from >> to >> time >> cost;
			edge e;
			e.from = from, e.to = to, e.time = time, e.cost = cost;
			es[i] = e;
		}

		std::cin >> k;
		for(int j=0;j<k;j++){
			int start, end, type;
			std::cin >> start >> end >> type;
			std::cout << minimum_value(type, start, end) << std::endl;
		}
	}
}

C++: V\\\#include<stack>
#include<queue>
#include<vector>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
static const int INFTY = (1 << 21);
int main(){
	int n, m, a, b, cost, time;
	int kk, p, q, r;
	int sta_c[101][101];
	int sta_t[101][101];
	while (cin >> n >> m, n, m){
		for (int i = 0; i < 101; i++){
			for (int j = 0; j < 101; j++){
				sta_c[i][j] = sta_t[i][j] = INFTY;
			}
		}
		for (int i = 0; i < n; i++){
			cin >> a >> b >> cost >> time;
			sta_c[a][b] = cost; sta_c[b][a] = cost;
			sta_t[a][b] = time; sta_t[b][a] = time;
		}
		for (int k = 1; k <= m; k++){
			for (int i = 1; i <= m; i++){
				if (sta_c[i][k] == INFTY) continue;
				for (int j = 1; j <= m; j++){
					if (sta_c[k][j] == INFTY) continue;
					sta_c[i][j] = min(sta_c[i][j], sta_c[i][k] + sta_c[k][j]);
					sta_t[i][j] = min(sta_t[i][j], sta_t[i][k] + sta_t[k][j]);
				}
			}
		}
		cin >> kk;
		for (int i = 0; i < kk; i++){
			cin >> p >> q >> r;
			if (r == 0) cout << sta_c[p][q] << endl;
			else cout << sta_t[p][q] << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int MAX_INT = 10000;
int n, m;
int p, q, r;

int costMap[101][101];
int timeMap[101][101];
int visited[101];

class Node {
public:
	int cost, pos;
	Node(int p) {
		cost = 0;
		pos = p;
	}
	Node(int p, int c, const Node& pre) {
		cost = c + pre.cost;
		pos = p;
	}
	bool operator< (const Node& o) const {
		return cost > o.cost;
	}
};

int main () {
	while (cin >> n >> m, n || m) {
		for (int i = 0; i < m; i++) {
			fill(costMap[i], costMap[i] + m + 1, MAX_INT);
			fill(timeMap[i], timeMap[i] + m + 1, MAX_INT);
		}
		for (int i = 0; i < n; i++) {
			int a, b, cost, time;
			cin >> a >> b >> cost >> time;
			costMap[a][b] = costMap[b][a] = cost;
			timeMap[a][b] = timeMap[b][a] = time;
		}
		int k;
		for (cin >> k; k; k--) {
			cin >> p >> q >> r;
			fill(visited, visited + m + 1, MAX_INT);
			priority_queue<Node> que;
			que.push(Node(p));
			visited[p] = true;
			while (!que.empty()) {
				Node current = que.top();
				que.pop();
				if (current.pos == q) {
					cout << current.cost << endl;
					break;
				}
				for (int i = 1; i <= m; i++) {
					if (r) {
						if (timeMap[current.pos][i] != MAX_INT && timeMap[current.pos][i] + current.cost < visited[i]) {
							visited[i] = timeMap[current.pos][i] + current.cost;
							que.push(Node(i, timeMap[current.pos][i], current));
						}
					}
					else {
						if (costMap[current.pos][i] != MAX_INT && costMap[current.pos][i] + current.cost < visited[i]) {
							visited[i] = costMap[current.pos][i] + current.cost;
							que.push(Node(i, costMap[current.pos][i], current));
						}
					}
				}
			}
		}
	}
	return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
using namespace std;
#define INF 1e+8
int main() {
	int n,m;
	while(scanf("%d%d",&n,&m),(n|m)) {
		int d[101][101][2];
		for(int i = 0; i < 101; i++) {
			for(int j = 0; j < 101; j++) {
				d[i][j][0] = INF;
				d[i][j][1] = INF;
			}
		}
		for(int i = 0; i < n; i++) {
			int a,b,cost,time;
			scanf("%d%d%d%d",&a,&b,&cost,&time);
			a--;b--;
			d[a][b][0] = cost;
			d[b][a][0] = cost;
			d[a][b][1] = time;
			d[b][a][1] = time;
		}
		for(int k = 0; k < m; k++) {
			for(int i = 0; i < m; i++) {
				for(int j = 0; j < m; j++) {
					for(int l = 0; l < 2; l++) {
						d[i][j][l] = min(d[i][j][l],d[i][k][l] + d[k][j][l]);		
						d[j][i][l] = min(d[j][i][l],d[j][k][l] + d[k][i][l]);		
					}
				}
			}
		}
		int k;
		scanf("%d",&k);
		for(int i = 0; i < k; i++) {
			int p,q,r;
			scanf("%d%d%d",&p,&q,&r);
			p--;q--;
			printf("%d\n",d[p][q][r]);
		}
	}
	return 0;
}