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>

#define INFINITY (1001)

using namespace std;

int main(void)
{
	while (1){
	int time[300][300];
	int cost[300][300];
	int req[3][100];
	int n, m;
	
	cin >> n >> m;
	if (n == 0 && m == 0){
		break;
	}
	for (int i = 0; i < m; i++){
		for (int j = 0; j < m; j++){
			time[i][j] = cost[i][j] = INFINITY;
		}
	}
	for (int i = 0; i < n; i++){
		int a, b, t, c;
		cin >> a >> b >> c >> t;
		time[a - 1][b - 1] = time[b - 1][a - 1] = t;
		cost[a - 1][b - 1] = cost[b - 1][a - 1] = c;
	}
	
	for (int k = 0; k < m; k++){
		for (int i = 0; i < m; i++){
			for (int j = 0; j < m; j++){
				time[i][j] = min(time[i][j], time[i][k] + time[k][j]);
				cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
			}
		}
	}
	
	
	int req_count;
	cin >> req_count;
	for (int i = 0; i < req_count; i++){
		cin >> req[0][i] >> req[1][i] >> req[2][i];
	}
	
	for (int i = 0; i < req_count; i++){
		if (req[2][i] == 0){
			cout << cost[req[0][i] - 1][req[1][i] - 1] << endl;
		}
		else {
			cout << time[req[0][i] - 1][req[1][i] - 1] << endl;
		}
	}
	}
	return (0);
}

C++: #include <iostream>
using namespace std;

const int INF = 1000000000;

int main()
{
	while(false){
		int n, m;
		cin >> n >> m;

		if(n==0 && m==0)
			break;

		 int C[100][100];
		 int T[100][100];
	   for(int i=0; i<m; i++){
		   for(int j=0; j<m; j++){
			   if(i==j){
	         C[i][j] = T[i][j] = 0;
		     }else{
			     C[i][j] = T[i][j] = INF;
		     }
		   }
     }

	   for(int i=0; i<n; i++){
		   int a, b, c, t;
		   cin >> a >> b >> c >> t;

	     C[a-1][b-1] = C[b-1][a-1] = c;
		   T[a-1][b-1] = T[b-1][a-1] = t;
    }

    int k;
    int e[m][m];
    cin>>k;
    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
        e[i][j]=C[i][j];
      }
    }
    for(int k=0;k<m;k++){
      for(int i=0;i<m;i++){
        for(int j=0;j<m;j++){
          if(e[i][j]>e[i][k]+e[k][j]){
            e[i][j]=e[i][k]+e[k][j];
          }
        }
      }
    }
    for(int i=0;i<k;i++){
      int p, q, r;
      int a=0;
      cin>>p>>q>>r;
      int d[m][m];
      if(r==0){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            d[i][j]=C[i][j];
          }
        }
        a=d[p-1][q-1];
        cout<<a<<endl;
      }
      if(r==1){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            d[i][j]=T[i][j];
          }
        }
        a=d[p-1][q-1];
        cout<<a<<endl;
      }
    }
	}

	return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;

const int inf = 1e8;
int m,n;
//n経路の数（枝）　m駅の数（葉）
struct edge{
  int from,to,cost,time;
  edge(int from,int to,int cost,int time): from(from), to(to), cost(cost), time(time){}
};

vector<edge> es;
int shortest_path(int s,int e,int v){
  int d[m];
  for(int i = 0 ; i < n ; i ++)d[i] = inf;
  d[s] = 0 ;
  while(true){
    bool updata = false;
    for(int i = 0 ; i < n ; i ++){
      edge e = es[i];
      if(d[e.from] != inf && d[e.to]> d[e.from] + e.cost && v == 0){
	d[e.to] = d[e.from] + e.cost;
	updata = true;
      }

      if(d[e.from] != inf && d[e.to]> d[e.from] + e.time && v == 1){
	d[e.to] = d[e.from] + e.time;
	updata = true;
      }
    } 
    if(!updata) break;
  }
  return d[e];
}

int main(void){
  while(cin>>n>>m,m+n){
    for(int i = 0 ; i < n ; i ++){
      int s,t,c,ti;
      cin>>s>>t>>c>>ti;
      s--; t--;
      es.push_back(edge(s,t,c,ti));
    }
    int num;
    cout<<num<<endl;
    for(int i = 0 ; i < num ;  i++){
      int s,t,v;
      cin>>s>>t>>v;
      s--; t--;
      //cout<<s <<" " << t << " " << v<<" ";
      cout<<shortest_path(s,t,v)<<endl;
    }
  }
  
    
}

C++: #include<cstdio>
#include<algorithm>
#include<iostream>
#include<vector>
#include<set>
#include<queue>

using namespace std;

#define rep(i,n) for(int i=0;i<int(n);i++)
#define reps(i,n) for(int i=1;i<=int(n);i++)

class L{
	public:
	int a,c,t;
	L(int a,int c,int t):a(a),c(c),t(t){}
};

class S{
	public:
	int now;
	int p;
	S(int now,int p):now(now),p(p){}
	bool operator<(const S&a)const{
		return p>a.p;
	}
};

int main(){
	
	while(1){
		int n,m;
		cin>>n>>m;
		
		if(n==0)break;
		
		vector<L> load[111];
		
		rep(i,n){
			int a,b,c,t;
			cin>>a>>b>>c>>t;
			
			load[a].push_back(L(b,c,t));
			load[b].push_back(L(a,c,t));
		}
		
		
		int k;
		cin>>k;
		
		rep(pp,k){
			int aa,bb,cc;
			cin>>aa>>bb>>cc;
			
			priority_queue<S> que;
			que.push(S(aa,0));
			
			int visit[111]={0};
			while(1){
				if(que.empty())break;
				
				S u = que.top();
				que.pop();
				
				//printf("%d %d\n",u.now,u.p);
				
				if(u.now==bb){
					printf("%d\n",u.p);
					break;
				}
				
				if(visit[u.now]==1)continue;
				visit[u.now]=1;
				
				rep(i,load[u.now].size()){
					
					L e = load[u.now][i];
					
					if(cc==0){
						que.push(S(e.a, u.p+e.c));
					}else{
						que.push(S(e.a, u.p+e.t));
					}
				}
			}
		}
	}
}