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<bits/stdc++.h>
using namespace std;
#define INF 1<<29
int V;
vector<vector<vector<int> > > G;
int d[101];
bool used[101];

void dijkstra(int s,int r){
  memset(used,false,sizeof(used));
  fill(d,d+101,INF);
  d[s]=0;
  while(1){
    int id=-1;
    for(int i=1;i<=V;++i)
      if(!used[i] && (id==-1||d[id]>d[i]))
        id=i;
    if(id==-1) break;
    used[id]=true;
    for(int i=1;i<=V;++i)
      if(r)
        d[i]=min(d[i],d[id]+G[id][i][1]);
      else
        d[i]=min(d[i],d[id]+G[id][i][0]);
  }
}
int main(){
  int n;
  while(cin>>n>>V,n){
    G=vector<vector<vector<int>>>(V+1,vector<vector<int>>(V+1,vector<int>(2,INF)));
    for(int i=0;i<n;++i){
      int a,b,c,t; cin>>a>>b>>c>>t;
      G[a][b][0]=G[b][a][0]=c;
      G[a][b][1]=G[b][a][1]=t;
    }
    int k; cin>>k;
    for(int i=0;i<k;++i){
      int p,q,r; cin>>p>>q>>r;
      dijkstra(p,r);
      cout<<d[q]<<endl;
    }
    
  }
  
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#include<map>
#define pb push_back
#define INF 1000000000

using namespace std;
typedef pair<int,int> P;
int n;

struct edge{
	int to,cost;
	edge(int to,int cost):to(to),cost(cost){}
};
vector<vector<edge> > G1,G2;


int dijkstra1(int s,int t){
	priority_queue<P,vector<P> , greater<P> > que;
	vector<int> d(n,INF);
	d[s]=0;
	que.push(P(0,s));
	while(!que.empty()){
		P q=que.top();
		que.pop();
		int now=q.second,dist=q.first;
		if(now==t){
			return dist;
		}
		
		if(d[now]<dist)
			continue;
		
		for(int i=0;i<(int)G1[now].size();i++){
			if(G1[now][i].cost+dist<d[G1[now][i].to]){
				que.push(P(G1[now][i].cost+dist,G1[now][i].to));
				d[G1[now][i].to]=G1[now][i].cost+dist;
			}
		}
	}
	return -1;
	
}
int dijkstra2(int s,int t){
	priority_queue<P,vector<P> , greater<P> > que;
	vector<int> d(n,INF);
	d[s]=0;
	que.push(P(0,s));
	while(!que.empty()){
		P q=que.top();
		que.pop();
		int now=q.second,dist=q.first;
		if(now==t){
			return dist;
		}
		
		if(d[now]<dist)
			continue;
		
		for(int i=0;i<(int)G2[now].size();i++){
			if(G2[now][i].cost+dist<d[G2[now][i].to]){
				que.push(P(G2[now][i].cost+dist,G2[now][i].to));
				d[G2[now][i].to]=G2[now][i].cost+dist;
			}
		}
	}
	return -1;
}
int main(){
	int m;
	while(cin>>m>>n,n||m){
		
		G1.resize(n);
		G2.resize(n);
		cout<<m<<endl;
		for(int i=0;i<m;i++){
			int a,b,c,t;
			cin>>a>>b>>c>>t;a--;b--;
			G1[a].pb(edge(b,c));
			G1[b].pb(edge(a,c));
			G2[a].pb(edge(b,t));
			G2[b].pb(edge(a,t));
		}
		cout<<G1[0].size()<<endl;
		
		int k;
		cin>>k;
		for(int i=0;i<k;i++){
			int p,q,r;
			cin>>p>>q>>r;p--,q--;
			if(r==0){
				cout<<dijkstra1(p,q)<<endl;
			}else
			cout<<dijkstra2(p,q)<<endl;
			
			
		}
		
	}
	
	return 0;
}

C++: #include <iostream>
#include <cctype>
#include <algorithm>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <utility>
#include <string>
#include <functional>
#include <cctype>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
typedef long long ll;
const int INF = 100000000, mod = 1000000007;
const ll LLINF = 1LL << 50;
using namespace std;

struct edge { int to, cos, tim; };
typedef pair<int, int> P;
vector<edge> G[105];
int n, m, k, cost[105], ti[105];

void dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> costque, timeque;
    fill(cost, cost + m + 1, INF);
    fill(ti, ti + m + 1, INF);
    cost[s] = 0;
    ti[s] = 0;
    costque.push(P(s, 0));
    timeque.push(P(s, 0));

    while (!costque.empty()) {
        P p = costque.top();
        costque.pop();
        int v = p.first;
        if (cost[v] < p.second) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (cost[e.to] > cost[v] + e.cos) {
                cost[e.to] = cost[v] + e.cos;
                costque.push(P(e.to, cost[e.to]));
            }
        }
    }
    while (!timeque.empty()) {
        P p = timeque.top();
        timeque.pop();
        int v = p.first;
        if (ti[v] < p.second) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (ti[e.to] > ti[v] + e.tim) {
                ti[e.to] = ti[v] + e.tim;
                timeque.push(P(e.to, ti[e.to]));
            }
        }
    }
    return;
}

int main() {
    while (1) {
        cin >> n >> m;
        if (n == 0 && m == 0) break;
        for (int i = 0; i < n; i++) {
            int a, b, c, t;
            cin >> a >> b >> c >> t;
            edge tmp = { b,c,t };
            G[a].push_back(tmp);
        }
        cin >> k;
        for (int i = 0; i < k; i++) {
            int p, q, r;
            cin >> p >> q >> r;
            dijkstra(p);
            if (r == 0) cout << cost[q] << endl;
            else cout << ti[q] << endl;
        }
    }
    return 0;
}