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<queue>
#include<cstdio>
#include<algorithm>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

template<class T>
class d_heap{
	static const int N_MAX=3000; // !!
	int n,d;
	T a[N_MAX];
public:
	d_heap(int d):n(0),d(d){}
	const T &find_min()const{ return a[0]; }
	void insert(const T &x){
		int u=n++;
		a[u]=x;
		while(u!=0 && a[(u-1)/d]>a[u]) swap(a[(u-1)/d],a[u]), u=(u-1)/d;
	}
	void delete_min(){
		a[0]=a[--n];
		for(int u=0;;){
			int v=u;
			for(int w=d*u+1;w<=d*u+d;w++) if(w<n && a[v]>a[w]) v=w;
			if(v==u) break;
			swap(a[v],a[u]);
			u=v;
		}
	}
	bool empty()const{ return n==0; }
	int size()const{ return n; }
};

#define define_heap d_heap< pair<int,int> > H(2);

const int INF=1<<29;

struct edge{ int v,cost1,cost2; };

int main(){
	for(int m,n;scanf("%d%d",&m,&n),n;){
		vector<edge> G[100];
		rep(i,m){
			int u,v,cost1,cost2; scanf("%d%d%d%d",&u,&v,&cost1,&cost2); u--; v--;
			G[u].push_back((edge){v,cost1,cost2});
			G[v].push_back((edge){u,cost1,cost2});
		}

		int q; scanf("%d",&q);
		while(q--){
			int s,t,type; scanf("%d%d%d",&s,&t,&type); s--; t--;

			int d[100];
			rep(u,n) d[u]=(u==s?0:INF);
			define_heap;
			H.insert(make_pair(0,s));
			while(!H.empty()){
				int d_now=H.find_min().first,u=H.find_min().second;
				H.delete_min();

				if(d[u]<d_now) continue;

				rep(i,G[u].size()){
					const edge &e=G[u][i];
					int d2=d_now+(type==0?e.cost1:e.cost2);
					if(d[e.v]>d2){
						d[e.v]=d2;
						H.insert(make_pair(d2,e.v));
					}
				}
			}

			printf("%d\n",d[t]);
		}
	}

	return 0;
}

C++: #include <bits/stdc++.h>
#define INF 114514810
#define FOR(i, r, n) for(int i=(r); i<(n); i++) 
#define REP(i, n) FOR(i, (0), n)

using namespace std;

int n, a, b, c, d, t = 0, sum = INF, ans, nodes = 0, p, q, r, w;
int x[102][102], y[102][102];

int main(){
	while (true){
		cin >> n >> nodes;
		if (n == 0 && nodes == 0) break;
		REP(i, 101)
			REP(j, 101){
			x[i][j] = (i == j ? 0 : INF);
			y[i][j] = (i == j ? 0 : INF);
		}
		REP(i, n){
			cin >> a >> b >> c >> d;
			x[a-1][b-1] = x[b-1][a-1] = c;
			y[a-1][b-1] = y[b-1][a-1] = d;
		}
		REP(k, nodes)
			REP(i, nodes)
			REP(j, nodes){
			x[i][j] = min(x[i][j], x[i][k] + x[k][j]);
			y[i][j] = min(y[i][j], y[i][k] + y[k][j]);
		}
		cin >> w;
		REP(k, w){
			cin >> p >> q >> r;
			if (r) cout << y[p-1][q-1] << endl;
			else cout << x[p-1][q-1] << endl;
		}
	}
}

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

inline int max(int a, int b) { if (a>b) return a; else return b; }
inline int min(int a, int b) { if (a<b) return a; else return b; }

int min_route(int matrix[101][101], int n, int a, int b)
{
  int cost[101];
  bool done[101];
  int min_s = a;
  const int MAX = 999999999;

  for (int i=1; i<=n; i++)
  {
    cost[i] = MAX;
    done[i] = false;
  }
  cost[a] = 0;
  while (!done[b])
  {
    done[min_s] = true;
    for (int i=1; i<=n; i++)
    {
      if ((matrix[min_s][i] > 0) && (cost[i] > cost[min_s]+matrix[min_s][i]))
      {
        cost[i] = cost[min_s]+matrix[min_s][i];
      }
    }
    int minin = MAX;
    for (int i=1; i<=n; i++)
    {
      if ((!done[i]) && (minin > cost[i]))
      {
        min_s = i;
        minin = cost[i];
      }
    }
  }
  return cost[b];
}


int main()
{
  int time[101][101];
  int cost[101][101];
  int n, m;                     // n: ?????±?????°, m: ?§??????°
  int a, b, c, t;

  cin >> n >> m;

  for (int i=1; i<=m; i++)
    for (int j=1; j<=m; j++) { time[i][j] = 0; cost[i][j] = 0; }

  for (int i=0; i<n; i++)
  {
    cin >> a >> b >> c >> t;
    time[a][b] = t;
    time[b][a] = t;
    cost[a][b] = c;
    cost[b][a] = c;
  }

  int k;                        // ?????¨????????°
  int p, q, r;                  // r=0:????°??????? 1:????????????
  cin >> k;
  for (int i=1; i<=k; i++)
  {
    cin >> p >> q >> r;
    if (r==0)
    {
      cout << min_route(cost, m, p, q) << endl;
    }
    else
    {
      cout << min_route(time, m, p, q) << endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
const int INF = 1000000;
int cost[301][301],time[301][301];
int main(){
	int n,m;
	while(cin >> n >> m,n || m){
		int a,b,icost,itime,c,r;
		for(int i = 0;i <= m;++i){
			for(int j = 0;j <= m;++j){
				if(i == j) {
					cost[i][i] = 0;
					time[i][i] = 0;
				}
				else {
					cost[i][j] = INF;
					time[i][j] = INF;
				}
			}
		}
		for(int i = 0;i < n;++i){
			cin >> a >> b >> icost >> itime;
			cost[a][b] = cost[b][a] = icost;
			time[a][b] = time[b][a] = itime;
		}
		cin >> c;
		for(int d = 0;d < c;++d){
			cin >> a >> b >> r;
			for(int k = 0;k <= m;++k){
				for(int i = 0;i <= m;++i){
					for(int j = 0;j <= m;++j){
						if(r == 1) time[i][j] = min(time[i][j],time[i][k] + time[k][j]);
						else cost[i][j] = min(cost[i][j],cost[i][k] + cost[k][j]);
					}
				}
			}
			if(r == 1) cout << time[a][b] << endl;
			else cout << cost[a][b] << endl;
		}
	}
	return 0;
}