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;

#define INF 100000000

struct edge {
	int to;
	int c, t;
};

int main() {
	int n, m, f, temp, s, k, p, q, r;
	vector<edge> g[101];
	queue<int> search;
	int mc[101][101], mt[101][101];
	edge e;
	cin >> n >> m;
	for(int i=0; i<=m; ++i) for(int j=0; j<=m; ++j) {
		mc[i][j] = mt[i][j] = INF;
	}
	for(int i=0; i<n; ++i) {
		cin >> f >> e.to >> e.c >> e.t;
		g[f].push_back(e);
		temp = e.to; e.to = f; f = temp;
		g[f].push_back(e);
	}
	for(int i=1; i<=m; ++i) {
		search.push(i); mc[i][i] = 0;
		while(!search.empty()) {
			s = search.front(); search.pop();
			for(vector<edge>::iterator it=g[s].begin(); it!=g[s].end(); ++it) {
				if(mc[i][s]+(*it).c<mc[i][(*it).to]) {
					mc[i][(*it).to] = mc[i][s]+(*it).c;
					search.push((*it).to);
					cout << i << " : " << s << " -> " << (*it).to << " = " << mc[i][(*it).to] << endl;
				}
			}
		}
		search.push(i); mt[i][i] = 0;
		while(!search.empty()) {
			s = search.front(); search.pop();
			for(vector<edge>::iterator it=g[s].begin(); it!=g[s].end(); ++it) {
				if(mt[i][s]+(*it).t<mt[i][(*it).to]) {
					mt[i][(*it).to] = mt[i][s]+(*it).t;
					search.push((*it).to);
				}
			}
		}
	}
	cin >> k;
	for(int i=0; i<k+1; ++i) {
		cin >> p >> q;
		if(!p&&!q) break;
		cin >> r;
		cout << (!r?mc[p][q]:mt[p][q]) << endl;
	}
	
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<functional>
using namespace std;
#define INF 10000000
#define PAIR pair<int,int>
class road {
public:
	int to;
	int money;
	int time;
	road(int a, int b, int c) :to(a), money(b), time(c) {}
};

vector<vector<int> > cost, fast;
vector<vector<road> > map;
void input(int);

int ccost(int, int);
int cfast(int, int);
int main() {
	int num, station;
	while (cin >> num >> station&&num != 0) {
		map.resize(station + 1);
		cost.resize(station + 1);
		fast.resize(station + 1);
		for (int i = 1; i <= station; ++i) {
			cost[i].resize(station + 1);
			fast[i].resize(station + 1);
			for (int j = 1; j <= station; ++j) {
				cost[i][j] = fast[i][j] = INF;
			}
		}
		input(num);
		int time;
		cin >> time;
		for (int i = 0; i < time; ++i) {
			int from, to, kind;
			cin >> from >> to >> kind;
			if (kind == 0) {
				cout << ccost(from, to) << endl;
			}
			else {
				cout << cfast(from, to) << endl;
			}
		}
		map.clear();
		fast.clear();
		cost.clear();
	}
	return 0;
}

int ccost(int from, int to) {
	int res = min(cost[from][to], cost[to][from]);
	if (res != INF)return res;
	priority_queue<PAIR, vector<PAIR>, greater<PAIR> > que;
	que.push(PAIR(0, from));
	cost[from][from] = 0;
	while (!que.empty()) {
		PAIR d = que.top();
		que.pop();
		if (d.first != cost[from][d.second]) {
			continue;
		}
		for (int i = 0; i < map[d.second].size(); ++i) {
			int dcost = d.first + map[d.second][i].money;
			int to = map[d.second][i].to;
			if (dcost < cost[from][to]) {
				cost[from][to] = dcost;
				que.push(PAIR(dcost, to));
			}
		}
	}
	return cost[from][to];
}
int cfast(int from, int to) {
	int res = min(fast[from][to], fast[to][from]);
	if (res != INF)return res;
	priority_queue<PAIR, vector<PAIR>, greater<PAIR> > que;
	que.push(PAIR(0, from));
	fast[from][from] = 0;
	while (!que.empty()) {
		PAIR d = que.top();
		que.pop();
		if (d.first != fast[from][d.second]) {
			continue;
		}
		for (int i = 0; i < map[d.second].size(); ++i) {
			int dtime = d.first + map[d.second][i].time;
			int to = map[d.second][i].to;
			if (dtime < fast[from][to]) {
				fast[from][to] = dtime;
				que.push(PAIR(dtime, to));
			}
		}
	}
	return fast[from][to];
}
void input(int num) {
	int a, b, cost, time;
	for (int i = 0; i < num; ++i) {
		cin >> a >> b >> cost >> time;
		map[b].push_back(road(a, cost, time));
		map[a].push_back(road(b, cost, time));
	}
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
#define MIN(a, b) ((a)<(b)?(a):(b))
#define MAX(a, b) ((a)<(b)?(a):(b))
#define INF 10e6
using namespace std;
 /*temp*/

int main(){
    int n, m, l;
    while(cin>>m>>n,n){
        int cost[n][n],time[n][n];
        // set table
        REP(i,n){
            REP(j,n){
                cost[i][j]=time[i][j]=INF;
            }
            cost[i][i]=time[i][i]=0;
        }
        // read
        REP(i,n){
            int a,b,c,t;
            a--;
            b--;
            cost[a][b]=cost[b][a]=MIN(c,cost[a][b]);
            time[a][b]=time[b][a]=MIN(t,time[a][b]);
        }
        // Warshall???Floyd Algorithm
        REP(a,n){
            REP(b,n){
                REP(k,n){
                    cost[a][b]=cost[b][a]=MIN(cost[a][b],cost[a][k]+cost[k][b]);
                    time[a][b]=time[b][a]=MIN(time[a][b],time[a][k]+time[k][b]);
                }
            }
        }
        // 
        int q;
        cin>>q;
        REP(i,q){
            int s,d,type;
            cin>>s>>d>>type;
            s--;
            d--;
            cout<<type==0?cost[s][d]:time[s][d]<<'\n';
        }
    }
    return 0;
}