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<stdio.h>
#define INF 1000000
typedef struct{
	short to,cost,time;
}edge;
int n,m;
int i,j,k;
int p,q,r;
edge e[100][3000];
int ce[100];
bool used[100];
int d[100];

int min(int a,int b){return a<b?a:b;}

int solve(int p,int q,int r){
	int l;
	for(l=0;l<m;l++){
		used[l]=false;
		d[l]=INF;
	}
	d[p]=0;
	int next;
	while(1){
		next=-1;
		for(l=0;l<m;l++){
			if(!used[l]&&(next==-1||d[next]>d[l]))next=l;
		}
		if(next==-1)break;
		used[next]=true;
		for(l=0;l<ce[next];l++){
			if(r==0)d[e[next][l].to]=min(d[e[next][l].to],d[next]+e[next][l].cost);
			if(r==1)d[e[next][l].to]=min(d[e[next][l].to],d[next]+e[next][l].time);
		}
	}
	return d[q];
}

int main(){
	while(1){
		scanf("%d %d",&n,&m);
		if(n==0&&m==0)return 0;
		for(i=0;i<m;i++)ce[i]=0;
		for(i=0;i<n;i++){
			int a,b,cost,time;
			scanf("%d %d %d %d",&a,&b,&cost,&time);
			e[a-1][ce[a-1]].to=b-1;
			e[a-1][ce[a-1]].cost=cost;
			e[a-1][ce[a-1]].time=time;
			e[b-1][ce[b-1]].to=a-1;
			e[b-1][ce[b-1]].cost=cost;
			e[b-1][ce[b-1]].time=time;
			ce[a-1]++;
			ce[b-1]++;
		}
		scanf("%d",&k);
		int ans_c=INF,ans_t=INF;
		for(i=0;i<k;i++){
			scanf("%d %d %d",&p,&q,&r);
			if(r==0)ans_c=min(ans_c,solve(p-1,q-1,r));
			if(r==1)ans_t=min(ans_t,solve(p-1,q-1,r));
		}
		printf("%d\n%d\n",ans_c,ans_t);
	}
}

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

static const int MAX_ST = 100;
static const int INFTY  = ( 1 << 20 );

pair< int, int > AdjMt[MAX_ST][MAX_ST];	// UndirectedGraph | first : cost, second : time

int Min( const int& left, const int& right ) { return left > right ? right : left; }

int main()
{

	ios::sync_with_stdio( false );	// for speeding up

	int  info_n, sta_n, query_n, depplc, dest, cost, time;
	bool query_meth;

	while( cin >> info_n >> sta_n, info_n || sta_n ) {

		for( int i = 0; i < MAX_ST; i++ ) {
			for( int j = 0; j < MAX_ST; j++ ) AdjMt[i][j].first = AdjMt[i][j].second = INFTY;
		}

		for( int i = 0; i < info_n; i++ ) {

			cin >> depplc >> dest >> cost >> time;
			AdjMt[--depplc][--dest].first = AdjMt[dest][depplc].first  = cost;
			AdjMt[depplc][dest].second    = AdjMt[dest][depplc].second = time;

		}

		// Warshall-Floyd
		for( int k = 0; k < sta_n; k++ ) {
			for( int i = 0; i < sta_n; i++ ) {
				if( AdjMt[i][k].first == INFTY ) continue;
				for( int j = 0; j < sta_n; j++ ) {

					AdjMt[i][j].first  = Min( AdjMt[i][j].first , AdjMt[i][k].first  + AdjMt[k][j].first );
					AdjMt[i][j].second = Min( AdjMt[i][j].second, AdjMt[i][k].second + AdjMt[k][j].second );

				}
			}
		}

		cin >> query_n;
		for( int i = 0; i < query_n; i++ ) {

			cin >> depplc >> dest >> query_meth;
			depplc--; dest--;
			cout << ( !query_meth ? AdjMt[depplc][dest].first : AdjMt[depplc][dest].second ) << endl;

		}

	}

	return 0;

}

C++: #include<iostream>
#include<vector>
#include<cstring>
#define INF 10100
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
struct E
{
    unsigned int a,b,c;
    E(){};
    E(unsigned int a,unsigned int b,unsigned int c):a(a),b(b),c(c){};
};
E cs[610];
E ts[610];

unsigned int d[110];
int main()
{
    int n,m;
    while(cin>>n>>m)
    {
        if(n==0&&m==0)break;
        
        int a,b,c,t;
        rep(i,n)
        {
            cin>>a>>b>>c>>t;
            cs[i*2] = E(a,b,c);
            cs[i*2+1] = E(b,a,c);
            
            ts[i*2] = E(a,b,t);
            ts[i*2+1] = E(b,a,t);

        }
        int p,q,r,k;
        cin >> k;
        rep(i,k)
        {
            cin >> p >> q >> r;
            memset(d,INF,sizeof(d));
            d[p] = 0;
            bool update = false;
            if(r == 0)
            {
                while(1)
                {
                    update = false;
                    rep(j,n*2)
                    {
                        if((d[ cs[j].b] != INF) && d[cs[j].b] > d[cs[j].a] + cs[j].c )
                        {
                            d[cs[j].b] =  d[cs[j].a] + cs[j].c;
                            update = true;
                        }


                    }
                    if(!update) break;
                }
                cout << d[q] << endl;
            }
            else
            {
                while(1)
                {
                    update = false;
                    rep(j,n*2)
                    {
                        if(d[ ts[j].b] != INF && d[ts[j].b] > d[ts[j].a] + ts[j].c)
                        {
                            d[ts[j].b] =  d[ts[j].a] + ts[j].c;
                            update = true;
                        }
                    }
                    if(!update) break;
                }
                cout << d[q] << endl;
            }
        }
    }
    return 0;
}