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<iostream>
#include<math.h>
#include<string>
#include<vector>
#include<algorithm>
#include<queue>
using namespace std;
#define INF 100000000000

struct edge{
	int to;
	int cost;
	edge() {};
	edge(int a, int b) {
		to = a;
		cost = b;
	}
};

struct Node {
	int pos;
	int cost;
	Node() {};
	Node(int a, int b) {
		pos = a;
		cost = b;
	}
	bool operator <(const Node& rhs) const {
		return cost > rhs.cost;
	}
};

void dijkistra(int st, int TO,int V,vector<vector<edge> > graph) {
	priority_queue<Node> q;
	vector<int> d(V);
	for (int i = 0;i < V;i++) {
		d[i] = INF;
	}
	d[st] = 0;
	q.push(Node(st, 0));
	while (!q.empty()) {
		Node s = q.top(); q.pop();
		int pos = s.pos;
		for (int i = 0;i < graph[pos].size();i++) {
			int to = graph[pos][i].to;
			int cost = graph[pos][i].cost;
			if (d[pos] + cost < d[to]) {
				d[to] = d[pos] + cost;
				q.push(Node(to, d[to]));
			}

		}
	}
	cout << d[TO] << endl;
}
int partition(int A[],int p, int r) {
	int x = A[r];
	int i = p - 1;
	for (int j = p;j < r;j++) {
		if (x >= A[j]) {
			i = i + 1;
			swap(A[i], A[j]);
		}
	}
		swap(A[i + 1], A[r]);
		return i + 1;
}
void quicksort(int A[], int p, int r) {
	if (p < r) {
		int q = partition(A, p, r);
		quicksort(A, p, q-1);
		quicksort(A, q + 1, r);
	}
}

int getNumberOfCoin(int C[],int n,int m) {
	int T[50000];
	for (int j = 0;j <= n;j++) {
		T[j] = INF;
	}
	T[0] = 0;
	for (int i = 0;i < m;i++) {
		for (int j = 0;j <= n;j++) {
			if (j - C[i] >=0  ) {
				T[j] = min(T[j], T[j - C[i]] + 1);
			}
		}
	}
	return T[n];
}
int knapsack(int w, int n,int* v,int* ww) {
	int W[101][10001];
		for (int j = 0;j <= w;j++) {
			W[0][j] = 0;
		}
	for (int i = 0;i < n;i++) {
		for (int k = 0;k < n;k++){
			for (int j = 0;j <= w;j++) {
				if (j - ww[k] < 0) {
					W[i + 1][j] = W[i][j];
				}
				if (j - ww[i] >= 0) {
					W[i + 1][j] = max(W[i][j], W[i][j - ww[k]] + v[k]);

				}
			}
		}
	}
	return W[n][w];
}
int main() {
	int line, num;
	cin >> line >> num;
	vector<vector<edge> > COST(num);
	vector<vector<edge> > TIME(num);
	for (int i = 0;i < line;i++) {
		int a, b, cost, time;
		cin >> a>>b>>cost>>time;
		COST[a-1].push_back(edge(b-1, cost));
		COST[b-1].push_back(edge(a-1, cost));
		TIME[a-1].push_back(edge(b-1, time));
		TIME[b-1].push_back(edge(a-1, time));
	}
	int k;
	cin >> k;
	for (int i = 0;i < k;i++) {
		int p, TO, r;
		cin >> p >> TO >> r;
		if (r == 0) {
			dijkistra(p-1, TO-1, num, COST);
		}
		else  
			dijkistra(p-1, TO-1, num, TIME);
	}

	return 0;
	
}

int isPrime(int x) {
	if (x <= 1) return false;
	if (x>2 && x % 2 == 0) return false;
	for (int i = 2;i <= sqrt(x);i++) {
		if (x%i == 0) {
			return false;
		}
	}
	if (x == 2) return true;
	return true;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
 
int d[101][101];
int t[101][101],c[101][101];
int n,m;
const int INF = 10000000;
 
void warshall_floyd() {
 
  for ( int k = 0; k <= m; k++ ) {
    for ( int i = 0; i <= m; i++ ) {
      for ( int j = 0; j <= m; j++ ) {
    t[i][j] = min( t[i][j], t[i][k] + t[k][j] );
    c[i][j] = min( c[i][j], c[i][k] + c[k][j] );
      }
    }
  }
 
}
 
int main() {
 
  
  while ( cin >> n >> m, n || m ) {
    for ( int i = 0; i < 101; i++ ) {
      for ( int j = 0; j < 101; j++ ) {
    if ( i == j ) {
      t[i][j] = 0;
      c[i][j] = 0;
    } else {
      t[i][j] = INF;
      c[i][j] = INF;
    }
      }
    }
   
    for ( int i = 0; i  < n; i++ ) {
      int a,b,cost,time; cin >> a >> b >> cost >> time;
      t[a][b] = t[b][a] = time;
      c[a][b] = c[b][a] = cost;
    }
    warshall_floyd();
    int k; cin >> k;
    for ( int i = 0; i < k; i++ ) {
      int p,q,r; cin >> p >> q >> r;
      if ( r == 0 ) {
    cout << c[p][q] << endl;
      } else if ( r == 1) {
    cout << t[p][q] << endl;
      }
    }
 
  }
  return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 1000000007
#define EPS 1e-10

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<double, double> PD;
typedef pair<string, ll> PS;
typedef vector<ll> V;
typedef pair<P, char> PC;


int dpt[111][111];
int dpc[111][111];
int n, m, a, b, cost, time, k, p, q, r;

int main(){
	while (cin >> n >> m&&n + m){
		REP(i, 111)REP(j, 111){
			if (i == j){
				dpt[i][j] = 0;
				dpc[i][j] = 0;
			}
			else{
				dpt[i][j] = INF;
				dpc[i][j] = INF;
			}
		}
		REP(i, n){
			cin >> a >> b >> cost >> time;
			dpt[a][b] = time;
			dpt[b][a] = time;
			dpc[a][b] = cost;
			dpc[b][a] = cost;
		}
		FOR(i, 1, m + 1){
			FOR(j, 1, m + 1){
				FOR(k, 1, m + 1){
					dpt[i][j] = min(dpt[i][j], dpt[i][k] + dpt[k][j]);
					dpc[i][j] = min(dpc[i][j], dpc[i][k] + dpc[k][j]);
				}
			}
		}
		cin >> k;
		REP(i, k){
			cin >> p >> q >> r;
			if (r == 0)cout << dpc[p][q] << endl;
			else cout << dpt[p][q] << endl;
		}
	}
}