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]
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[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 <cstdio>
#include <iomanip>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <utility>
#include <numeric>
#include <algorithm>
#include <functional>
#include <cctype>
#include <complex>
#include <string>
#include <sstream>
#include <cassert>
using namespace std;

//common
typedef int  i32;
typedef long long i64,ll;
#define BR "\n"

#define ALL(c) (c).begin(),(c).end()
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define EACH(it,o) for(auto it = (o).begin(); it != (o).end(); ++it)
#define IN(l,v,r) ((l)<=(v) && (v)<(r))

typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;

//config
#define MODE_DEBUG
//#define INF 1<<30
//#define EPS 1e-8
//const ll MOD =100000007;

//debug
#ifdef MODE_DEBUG
#define LINE()    cerr<< " (L" << __LINE__ << ")"
#define LINELN()    LINE()<<endl

#define  DUMP(x)  cerr << #x << " = " << (x) <<endl
#define DEBUG(x) DUMP(x) << " (L" << __LINE__ << ")" << " " << __FILE__<<endl
#define CHECK(exp,act)  if(exp!=act){DUMP(exp);DEBUG(act);}
#define STOP(e)  CHECK(e,true);if(!(e)) exit(1);
#else
#define DUMP(x)
#define DEBUG(x)
#define CHECK(exp,act)
#define STOP(e)
#endif

template<class T> inline string toString(const vector<T>& x) {
	stringstream ss;
	REP(i,x.size()){
		if(i!=0)ss<<" ";
		ss<< x[i];
	}
	return ss.str();
}
template<class T> inline string toString(const vector<vector<T>>& map) {
	stringstream ss;
	REP(i,map.size()){
		if(i!=0)ss<<BR;
		ss<< toString(map[i]);
	}
	return ss.str();
}
template<class K,class V>  string toString(map<K,V>& x) {
	string res;stringstream ss;
	for(auto& p:x)ss<< p.first<<":" << p.second<<" ";
	return ss.str();
}

template<typename T,typename V> inline T mod(T v,V MOD){
	return (v%MOD+MOD)%MOD;
}

typedef vector<vector<int>> Mat;
void warshall_floyd(Mat& d){
    const int V=d.size();
    for(int k=0;k<V;k++)
        for(int i=0;i<V;i++)for(int j=0;j<V;j++)
            if(d[i][j]>d[i][k] + d[k][j]){
                d[i][j]=d[i][k] + d[k][j];
                //prev[i][j]=k;
            }
}

const int INF =1<<28;
int main(){

	while(true){
		int N,M;cin >> N >> M;
		if(N==0 && M==0)return 0;
		Mat ds(M+1,vector<int>(M+1,INF));
		Mat cs(M+1,vector<int>(M+1,INF));
		REP(i,M+1)ds[i][i]=cs[i][i]=0;

		REP(i,N){
			int a,b,c,t; cin >> a >> b >> c>>t;
			ds[a][b]=min(ds[a][b],t);ds[b][a]=min(ds[b][a],t);

			cs[a][b]=min(cs[a][b],c);cs[b][a]=min(cs[b][a],c);
		}
		warshall_floyd(ds);DUMP(toString(ds));
		warshall_floyd(cs);DUMP(toString(cs));
		int k;cin >> k;
		REP(i,k){
			int p,q,r;cin >> p >> q >>r;
			if(r==0)cout<<cs[p][q]<<endl;
			else cout<<ds[p][q]<<endl; 
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>

#define INF (1e9)

#define MAX_N 3000
#define MAX_M 100

using namespace std;

int cost[MAX_M + 1][MAX_M + 1][2];

int N,M;
int K;


void init(){
	for(int i = 0;i <= MAX_M;i++){
		for(int j = 0;j <= MAX_M;j++){
			for(int k = 0;k < 2;k++){
				if(i != j) cost[i][j][k] = INF;
				else cost[i][j][k] = 0;
			}
		}
	}

	return ;
}

void solve(){
	for(int k = 1;k <= M;k++){
		for(int i = 1;i <= M;i++){
			for(int j = 1;j <= M;j++){
				for(int h = 0;h < 2;h++){
					cost[i][j][h] = min(cost[i][j][h],cost[i][k][h] + cost[k][j][h]);
				}
			}
		}
	}


	return ;
}

int query(int u,int v,int r){
	return cost[u][v][r];
}

int main(){

	while(true){
		init();
		scanf("%d%d",&N,&M);
		if(N == 0 && M == 0) break;
		int _u,_v;
		int _c,_t;
		for(int i = 0;i < N;i++){
			scanf("%d%d%d%d",&_u,&_v,&_c,&_t);
			cost[_u][_v][0] = _c;
			cost[_v][_u][0] = _c;
			cost[_u][_v][1] = _t;
			cost[_v][_u][1] = _t;
		}
	
		solve();
	
		scanf("%d",&K);
		int _r;
		for(int i = 0;i < K;i++){
			scanf("%d%d%d",&_u,&_v,&_r);
			printf("%d\n",query(_u,_v,_r));
		}
	}

	return 0;

}

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<functional>
#include<iostream>
#include<queue>
#define rep(i,a,b) for(i=a;i<b;i++)
#define F1 first.first
#define F2 first.second
#define F3 second
#define INF 2100000000
#define long long int int
using namespace std;
typedef pair<pair<int,int>,int> P1;
typedef pair<int,int> P2;
int main(void)
{
	int i,j,k,n,m,x,s,e;
	int a,b,cos,tim,st,en,way;
	int leng[1002],kami[1002];
	P1 glid1[6000],glid2[6000];
	P2 tori;
	while(cin>>n>>m,n&&m) {
		rep(i,0,n) {
			cin>>a>>b>>cos>>tim;
			glid1[i*2].F1=a,glid1[i*2].F2=b,glid1[i*2].F3=cos;
			glid2[i*2].F1=a,glid2[i*2].F2=b,glid2[i*2].F3=tim;
			glid1[i*2+1].F1=b,glid1[i*2+1].F2=a,glid1[i*2+1].F3=cos;
			glid2[i*2+1].F1=b,glid2[i*2+1].F2=a,glid2[i*2+1].F3=tim;
		}
		sort(glid1,glid1+m*2);sort(glid2,glid2+m*2);
		kami[1]=0;
		rep(i,1,m*2) {
			if(glid1[i].F1!=glid1[i-1].F1) {
				x=glid1[i].F1;
				kami[x]=i;
			}
		}
		kami[n+1]=m*2;
		priority_queue<P2,vector<P2>,greater<P2> > que;
		cin>>k;
		rep(i,0,k) {
			cin>>st>>en>>way;
			for(j=1;j<=n;j++) leng[j]=INF;
			while(!que.empty()) que.pop();
			que.push(P2(0,st));
			while(!que.empty()) {
				tori=que.top(),que.pop();
				a=tori.first,b=tori.second;
				if(a<leng[b]) {
					leng[b]=a;
					if(b==en) break;
					s=kami[b],e=kami[b+1];
					if(way==0)rep(j,s,e) que.push(P2(a+glid1[j].F3,glid1[j].F2));
					else rep(j,s,e) que.push(P2(a+glid2[j].F3,glid2[j].F2));
				}
			}
			cout<<leng[en]<<endl;
		}
	}
	return 0;
}