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>
#include <iomanip>
#include <vector>
#include <set>
#include <map>
#include <list>
#include <iterator>
#include <queue>
#include <stack>
#include <deque>
#include <sstream>
#include <algorithm>
#include <numeric>
#include <string>
#include <cmath>
#include <complex>
#include <functional>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cstdlib>
#include <cctype>

#define REP(i,m,n) for(int i=m;i<(int)n;i++)
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define rp(i,c) rep(i,(int)c.size())
#define fr(i,c) for(__typeof((c).begin()) i=(c).begin();i!=(c).end();i++)
#define mp make_pair
#define pb push_back
#define all(c) (c).begin(),(c).end()
#define rall(u) (u).rbegin(),(u).rend()
#define dbg(x) cerr<<#x<<" = "<<(x)<<endl
#define v_delete(a,b) (a).erase(remove((a).begin(), (a).end(), b), (a).end())
#define v_unique(a) (a).erase(unique((a).begin(), (a).end()), (a).end())
#define VV(T) vector<vector< T > >
#define init(a,b) memset((a), (b), sizeof((a)))
using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pii;
const int inf=1<<28;
const double INF=1e10,EPS=1e-9;


template<class T>int SIZE(T a){return a.size();}
template<class T>string IntToString(T num){string res;stringstream ss;ss<<num;return ss.str();}
template<class T>T StringToInt(string str){T res=0;for(int i=0;i<SIZE(str);i++)res=(res*10+str[i]-'0');return res;}
template<class T>T gcd(T a,T b){if(b==0)return a;return gcd(b,a%b);}
template<class T>T lcm(T a,T b){return a/gcd(a,b)*b;}

template <class T> void input(T& a, int n) { for (int i = 0; i < n; ++i) cin >> a[i]; }
template <class T> void input(T* a, int n) { for (int i = 0; i < n; ++i) cin >> a[i]; }

int in(){
	int t;
	cin >> t;
	return t;
}

struct sta{
	vi edges;
	vi costs;
	vi times;

};

int main()
{

	while(1){
		int n,m,k;
		cin >> n >> m;
		if(n==0 && m==0)
			break;
		vector<sta>stations(m);

		rep(i,n){
			int a,b,cost,time;
			cin >> a >> b >> cost >> time;
			a--;
			b--;
			stations[a].edges.pb(b);
			stations[a].costs.pb(cost);
			stations[a].times.pb(time);
			stations[b].edges.pb(a);
			stations[b].costs.pb(cost);
			stations[b].times.pb(time);
		}
		cin >> k;
		rep(i,k){
			int s,g,q;
			cin >> s >> g >> q;
			s--;
			g--;
			if(!q){
				priority_queue<pii,vector<pii>,greater<pii> > Q;
				vi cost(m,inf);
				cost[s]=0;
				Q.push(mp(0,s));
				while(!Q.empty()){
					pii f=Q.top();Q.pop();
					sta now=stations[f.second];
					if(cost[f.second] < f.first)continue;
					rp(i,now.edges){
						int to=now.edges[i];
						int cos=now.costs[i];
						if(cost[to] > f.first+cos){
							cost[to]=f.first+cos;
							Q.push(mp(cost[to],to));
						}
					}
				}
				cout << cost[g] << endl;
			}else{
				priority_queue<pii,vector<pii>,greater<pii> > Q;
				vi time(m,inf);
				time[s]=0;
				Q.push(mp(0,s));
				while(!Q.empty()){
					pii f=Q.top();Q.pop();
					sta now=stations[f.second];
					if(time[f.second] < f.first)continue;
					rp(i,now.edges){
						int to=now.edges[i];
						int ti=now.times[i];
						if(time[to] > f.first+ti){
							time[to]=f.first+ti;
							Q.push(mp(time[to],to));
						}
					}
				}
				cout << time[g] << endl;
			}
		}
	}
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#define _m_ 1
const int INF = 1e9;

int cost[101][101];
int tim[101][101];
int d[101];
bool used[101];
int V;

void dijkstra(int s, int o){
	std::fill(d, d + V, INF);
	std::fill(used, used + V, false);
	d[s] = 0;
	while(_m_){
		int v = -1;
		for(int u = 0; u < V; ++u){
			if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
		}
		if(v == -1)break;
		used[v] = true;
		if(o == 0){
			for(int u = 0; u < V; ++u){
				d[u] = std::min(d[u], d[v] + cost[v][u]);
			}
		}else {
			for(int u = 0; u < V; ++u){
				d[u] = std::min(d[u], d[v] + tim[v][u]);
			}
		}
	}
}

int main(){
	int n, m;
	while(scanf("%d %d",&n,&m), n+m){
		for(int i=0;i<n;++i){
			for(int j=0;j<n;++j){
				cost[i][j]=INF;
				tim[i][j]=INF;
			}
		}
		for(int i = 0; i < n; ++i){
			int a, b, co, ti;
			scanf("%d %d %d %d",&a, &b, &co, &ti);
			a--,b--;
			cost[a][b] = co, cost[b][a] = co;
			tim[a][b] = ti, tim[b][a] = ti;
		}
		V = m;
		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--;
			dijkstra(p, r);
			printf("%d\n", d[q]);
		}
	}
}