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 <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <queue>
#include <cstring>
#include <functional>

using namespace std;

#define REP(i,a,b) for((i)=(a);(i)<(int)(b);(i)++)
#define rep(i,n) REP(i,0,n)
#define foreach(itr,c) for(__typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++)

typedef pair<int, int> P;
const int INF = 1<<29;

int dijkstra(int s, int g, vector<vector<P> > & G){
  int i;
  int m = G.size();
  vector<int> d(m,INF);
  priority_queue<P,vector<P>,greater<P> > q;

  d[s] = 0;
  q.push(P(0,s));
  while(!q.empty()){
    P p = q.top(); q.pop();
    if(d[p.second] < p.first) continue;
    if(p.second == g) return d[g];

    rep(i,G[p.second].size()){
      P e = G[p.second][i];
      if(d[e.first] > d[p.second] + e.second){
        d[e.first] = d[p.second] + e.second;
        q.push(P(d[e.first], e.first));
      }
    }
  }
  return INF;
}

int main(){
  int n,m,k;
  vector<vector<P> > times, costs;

  while(scanf("%d %d", &n,&m)){
    if(n == 0 && m == 0) break;

    times.resize(m);
    costs.resize(m);
    while(n--){
      int from, to, cost, time;
      scanf("%d %d %d %d",&from,&to,&cost,&time);
      from--; to--;
      times[from].push_back(P(to,time));
      costs[from].push_back(P(to,cost));
    }

    scanf("%d",&k);
    while(k--){
      int s, g, bit;
      scanf("%d %d %d",&s,&g,&bit);
      s--; g--;

      if(bit == 0) printf("%d\n",dijkstra(s,g,costs));
      if(bit == 1) printf("%d\n",dijkstra(s,g,times));
    }
  }

  return 0;
}

C++: #include<iostream>

using namespace std;

int main(){
	int cost[101][101];
	int tims[101][101];
	
	while(1){
		int n,m;
		cin>>n>>m;
		if(n==0){
			break;
		}
		for(int i=0;i<101;i++){
			for(int j=0;j<101;j++){
				cost[i][j]=tims[i][j]=210000000;
			}
		}
		
		for(int i=0;i<n;i++){
			int a,b,c,d;
			cin>>a>>b>>c>>d;
			cost[a][b]=cost[b][a]=c;
			tims[a][b]=tims[b][a]=d;
		}
		
		for(int i=1;i<=m;i++){
			for(int j=1;j<=m;j++){
				for(int k=1;k<=m;k++){
					cost[i][j]=min(cost[i][j],cost[i][k]+cost[k][j]);
					tims[i][j]=min(tims[i][j],tims[i][k]+tims[k][j]);
				}
			}
		}
		
		int l;
		cin>>l;
		for(int i=0;i<l;i++){
			int a,b,c;
			cin>>a>>b>>c;
			if(c==0){
				printf("%d\n",cost[a][b]);
			}else{
				
				printf("%d\n",tims[a][b]);
			}
		}
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
const int INF = 1 << 28;


void Floyd_Warshall(vector< vector< int > >& graph){
  for(int k = 0; k < graph.size(); k++){
    for(int i = 0; i < graph.size(); i++){
      for(int j = 0; j < graph.size(); j++){
        graph[i][j] = min( graph[i][j], graph[i][k] + graph[k][j]);
      }
    }
  }
  return ;
}

int main() {
  int n, m;
  vector< vector< int > > graph1, graph2;

  while(cin >> n >> m, n){
    graph1.assign(m, vector< int >(m, INF));
    graph2.assign(m, vector< int >(m, INF));
    for(int i = 0; i < n; i++){
      int a, b, cost, time;
      cin >> a >> b >> cost >> time;
      --a, --b;
      graph1[a][b] = graph1[b][a] = cost;
      graph2[a][b] = graph2[b][a] = time;
    }
    Floyd_Warshall(graph1);
    Floyd_Warshall(graph2);

    int k;
    cin >> k;
    while(k--){
      int p, q, r;
      cin >> p >> q >> r;
      --p, --q;
      if(r == 0) cout << graph1[p][q] << endl;
      else cout << graph2[q][p] << endl;
    }
  }
}

C++: #include <iostream>
#include <vector>
#include <cmath>

#define INF 100000000

using namespace std;

int main()
{
    int n, m;
    while(true) {
        cin >> n >> m;
        if(n == 0 && m == 0) break;
        int times[n+1][n+1], costs[n+1][n+1];
        int a,b,cost,time;
        for(int i = 1; i <= n; i++) 
            for(int j = 1; j <= n; j++) 
                times[i][j] = costs[i][j] = (i==j) ? 0 : INF; 
        
        for(int i = 0; i < n; i++) {
            cin >> a >> b >> cost >> time;
            costs[a][b] = costs[b][a] = cost;
            times[a][b] = times[b][a] = time;
        }

        for(int a = 1; a <= n; a++) {
            for(int b = 1; b <= n; b++) {
                for(int c = 1; c <= n; c++) {
                    times[a][b] = min(times[a][b], times[a][c] + times[c][b]);
                    costs[a][b] = min(costs[a][b], costs[a][c] + costs[c][b]);
                }
            }
        }

        int p,q,r,qn;
        cin >> qn;
        for(int i = 0; i < qn; i++) {
            cin >> p >> q >> r;
            if(r == 1) 
                cout << times[p][q] << endl;
            else 
                cout << costs[p][q] << endl;
                     
        }
    }
    return 0;
}