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<iostream>
#include<vector>
#include<map>
#include<queue>
#include<functional>
#define INF 1000000000//INF=∞
using namespace std;
typedef pair<int, int> P;//firstは最短距離,secondは頂点番号
struct edge {
  int to, cost;
  edge() : to(0), cost(0) {}
  edge(int to, int cost) : to(to), cost(cost) {}
};
int V;//頂点の数
int dijkstra(vector<vector<edge> >& G, int s, int g){
  //Gは頂点間の距離情報(隣接リスト)
  priority_queue<P, vector<P>, greater<P> > que;
  vector<int> d(V, INF);//最短距離を記録する配列(∞で初期化しておく)
  d[s] = 0;//頂点sから頂点sへの最短距離は0で確定
  que.push(P(0, s));//距離0,頂点sからスタート

  while(!que.empty()){
    /*処理1*/
    //キューの中で最も頂点sからの距離が近い頂点vとその距離cを取得
    P p = que.top();
    que.pop();
    int v = p.second, c = p.first;

    /*処理2*/
    //頂点vの最短距離がすでに確定していたらcontenue
    if(d[v] < c)
      continue;

    /*処理3*/
    //頂点vの最短距離が既に確定していなければ頂点vへの最短経路はcで確定
      d[v]=c;

    /*処理4*/
    //頂点vから移動しうる頂点とその距離をキューに入れる
    for(int i = 0; i < G[v].size(); i++){
      //頂点vはG[v].size()個の行き先を持つ
      edge e = G[v][i];
      if(d[e.to] > d[v] + e.cost){
        que.push(P(d[v] + e.cost, e.to));
      }
    }
  }

  return d[g];//頂点gへの最短距離を返す
}


int main() {
  int n, m;
  while (cin >> n >> m, n || m) {
    V = m;
    vector<vector<edge> > time_graph(m);
    vector<vector<edge> > cost_graph(m);
    for (int i = 0; i < n; i++) {
      int a, b, time, cost;
      cin >> a >> b >> time >> cost;
      a--; b--; // 0-indexedにする
      
      time_graph[a].push_back(edge(b, time));
      time_graph[b].push_back(edge(a, time));
      cost_graph[a].push_back(edge(b, cost));
      cost_graph[b].push_back(edge(a, cost));
    }

    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 << dijkstra(time_graph, p, q) << endl;
      else
        cout << dijkstra(cost_graph, p, q) << endl;
    }
  }
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#define mod 1000000007
#define lol(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef pair<int,int> P;
typedef pair<int,P> PP;
int main(){
	int n,m;
	while(cin>>m>>n&&n+m){
		priority_queue<P,vector<P>,greater<P> >Q;
		vector<PP> v[110];
		int dis[110];
		lol(i,m){
			int a,b,c,d;
			cin>>a>>b>>c>>d;
			v[a].push_back(make_pair(b,make_pair(c,d)));
			v[b].push_back(make_pair(a,make_pair(c,d)));
		}
		cin>>m;
		lol(u,m){
			lol(i,n)dis[i+1]=mod;
			int s,t,c;cin>>s>>t>>c;
			Q.push(make_pair(s,0));
			while(!Q.empty()){
				int a=Q.top().first,b=Q.top().second;
				Q.pop();
				if(dis[a]<mod)continue;
				dis[a]=b;
				lol(i,v[a].size()){
					int to=v[a][i].first,co=b+(c?v[a][i].second.second:v[a][i].second.first);
					Q.push(make_pair(to,co));
				}
			}
			cout<<dis[t]<<endl;
		}
	}
	return 0;
}

C++: #include<iostream>
#define INF 100000000
using namespace std;
int min(int a,int b){
  if(a<b) return a;
  else return b;
}
int main(){
  int n,m;
  while(cin>>n>>m){
    if(n==0&&m==0) break;
    int d0[m+1][m+1],d1[m+1][m+1];
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
	d0[i][j] = INF;
	d1[i][j] = INF;
      }
    }
    int a,b,cost,time;
    for(int i=0;i<n;i++){
      cin >> a >> b >> cost >> time;
      d0[a][b] = cost;
      d0[b][a] = cost;
      d1[a][b] = time;
      d1[b][a] = time;
    }
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
	for(int k=1;k<=m;k++){
	  d0[i][j] = min(d0[i][j],d0[i][k]+d0[k][j]);
	  d1[i][j] = min(d1[i][j],d1[i][k]+d1[k][j]);
	}
      }
    }
    int s,p,q,r; 
    cin >> s;
    for(int i=0;i<s;i++){
      cin >> p >> q >> r;
      if(p==q) cout << 0 << endl;
      else if(r==0) cout << d0[p][q] << endl;
      else cout << d1[p][q] << endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
typedef pair<int, int> P;
const int INF = 1 << 28;
int c[101][101];
int t[101][101];
int cost[101][101];
int tim[101][101];

int main(){
  int n, m, K;
  int p, q, r;
  while(cin >> n >> m && (n || m)){
    fill(&cost[0][0], &cost[100][100] + 1, INF);
    fill(&tim[0][0], &tim[100][100] + 1, INF);
    fill(&c[0][0], &c[100][100] + 1, INF);
    fill(&t[0][0], &t[100][100] + 1, INF);
    for(int i = 1; i <= m; i++){
      cost[i][i] = tim[i][i] = 0;
    }
    for(int i = 0; i < n; i++){
      int a, b;
      cin >> a >> b;
      cin >> c[a][b] >> t[a][b];
      c[b][a] = c[a][b];
      t[b][a] = t[a][b];
    }
    for(int k = 1; k <= m; k++){
      for(int i = 1; i <= m; i++){
	for(int j = 1; j <= m; j++){
	  if(cost[i][j] > cost[i][k] + c[k][j]){
	    cost[i][j] = cost[i][k] + c[k][j];
	  }
	  if(tim[i][j] > tim[i][k] + t[k][j]){
	    tim[i][j] = tim[i][k] + t[k][j];
	  }
	}
      }
    }
    cin >> K;    
    for(int i = 0; i < K; i++){
      cin >> p >> q >> r;
      if(!r){
	cout << cost[p][q] << endl;
      }else{
	cout << tim[p][q] << endl;
      }
    }
  }
  return 0;
}