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<cstdio>
#include<vector>
#include<queue>
using namespace std;
int main(){
    for(;;){
        int n,m;
        scanf("%d%d",&n,&m);
        if(n==0&&m==0)break;
        vector<vector<int> > costs(m,vector<int>(m,-1));
        vector<vector<int> > times(m,vector<int>(m,-1));
        for(int i=0;i<n;i++){
            int a,b,cost,time;
            scanf("%d%d%d%d",&a,&b,&cost,&time);
            a--;b--;
            costs[a][b]=cost;
            costs[b][a]=cost;
            times[a][b]=time;
            times[b][a]=time;
        }
        int k;
        scanf("%d",&k);
        for(int i=0;i<k;i++){
            int p,q,r;
            scanf("%d%d%d",&p,&q,&r);
            p--;q--;
            if(r==1){
                vector<int> d(m,-1);
                d[p]=0;
                priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > lens;
                lens.push(make_pair(0,p));
                while(!lens.empty()){
                    pair<int,int> p = lens.top();
                    lens.pop();
                    int v=p.second;
                    if(d[v]<p.first)continue;
                    for(int j=0;j<m;j++){
                        if(times[v][j]!=-1&&(d[j]>d[v]+times[v][j]||d[j]==-1)){
                            d[j]=d[v]+times[v][j];
                            lens.push(make_pair(d[j],j));
                        }
                    }
                }
                printf("%d\n",d[q]);
            }else{
                vector<int> d(m,-1);
                d[p]=0;
                priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > lens;
                lens.push(make_pair(0,p));
                while(!lens.empty()){
                    pair<int,int> p = lens.top();
                    lens.pop();
                    int v=p.second;
                    if(d[v]<p.first)continue;
                    for(int j=0;j<m;j++){
                        if(costs[v][j]!=-1&&(d[j]>d[v]+costs[v][j]||d[j]==-1)){
                            d[j]=d[v]+costs[v][j];
                            lens.push(make_pair(d[j],j));
                        }
                    }
                }
                printf("%d\n",d[q]);
            }
        }
    }
}

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

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++)
#define sint(i) scanf("%d",&i);
#define sintt(i,j) scanf("%d%d",&i,&j);
#define sinttt(i,j,k) scanf("%d%d%d",&i,&j,&k);
#define sintttt(i,j,k,m) scanf("%d%d%d%d",&i,&j,&k,&m);

#define INF 1010000000
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};

int main(){
	while(1){
		int n,m;
		int time[101][101];
		int cost[101][101];
		
		rep(i,101)rep(j,101)time[i][j]=cost[i][j]=INF;
		
		sintt(n,m);
		if(n==0)break;
		rep(i,n){
			int a,b,c,d;
			sintttt(a,b,c,d);
			
			time[a][b]=d;
			time[b][a]=d;
			
			cost[a][b]=c;
			cost[b][a]=c;
		}
		
		reps(k,n){
			reps(i,n){
				reps(j,n){
					cost[i][j]=min(cost[i][j],cost[i][k]+cost[k][j]);
					time[i][j]=min(time[i][j],time[i][k]+time[k][j]);
				}
			}
		}
		
		int q;
		sint(q);
		rep(i,q){
			int a,b,c;
			sinttt(a,b,c);
			if(c==1){
				printf("%d\n",time[a][b]);
			}else{
				printf("%d\n",cost[a][b]);
			}
		}
	}
}