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 <cstdio>
#include <vector>

using namespace std;

class Edge{
public:
	int from,to,cost,time;
	void Swap(){
		int self = from;
		from = to;
		to = from;
	}
	int GetValue(int r){
		if(r == 0){
			return cost;
		}else{
			return time;
		}
	}
};

vector<Edge> edge;
int n,m;

const int INF = 100000000;

int solve(const int p,const int q,const int r);

int main(){
	scanf("%d %d",&n,&m);
	for(int i=0;i<n;i++){
		Edge ed;
		scanf("%d %d %d %d",&ed.from,&ed.to,&ed.cost,&ed.time);
		edge.push_back(ed);
		ed.Swap();
		edge.push_back(ed);
	}
	int k;
	int p,q,r;
	scanf("%d",&k);
	for(int i=0;scanf("%d %d",&p,&q) && p && q && i < k;i++){
		scanf("%d",&r);
		printf("%d\n",solve(p,q,r));
	}
	return 0;
}

int solve(const int p,const int q,const int r){
	vector<int> d(m+1);
	for(int i=0;i<=m;i++){
		d[i] = INF;
	}
	d[p] = 0;
	
	bool flag;
	while(1){
		flag = false;
		vector<Edge>::iterator it;
		for(it = edge.begin();it != edge.end();it++){
			if(d[(*it).from] != INF && d[(*it).to] > d[(*it).from] + (*it).GetValue(r)){
				d[(*it).to] = d[(*it).from] + (*it).GetValue(r);
				flag = true;
			}
		}
		if(!flag){
			break;
		}
	}
	
	return d[q];
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int MAX_INT = 10000000;
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 memo[101][101][2];

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 (int i = 0; i <= m; i++) {
			for (int j = 0; j <= m; j++) {
				memo[i][j][0] = 0x7fffffff;
				memo[i][j][1] = 0x7fffffff;
			}
		}
		for (cin >> k; k; k--) {
			cin >> p >> q >> r;
			if (memo[p][q][r] != 0x7fffffff) {
				cout << memo[p][q][r] << endl;
			}
			fill(visited, visited + m + 1, MAX_INT);
			priority_queue<Node> que;
			que.push(Node(p));
			visited[p] = 0;
			while (!que.empty()) {
				Node current = que.top();
				que.pop();
				if (current.pos == q) {
					cout << current.cost << endl;
					memo[p][q][r] = memo[q][p][r] = current.cost;
					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));
							//cout << current.pos << " to " << i << endl;
						}
					}
					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));
							//cout << current.pos << " to " << i << endl;
						}
					}
				}
			}
		}
	}
	return 0;
}