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]
					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;

// #include"binary_heap.cpp"
// #include"d_heap.cpp"
// #include"pqueue.cpp"

template<class T>
class d_heap_for_Dijkstra{
	static const int N_MAX=3000;
	int n,d,key[N_MAX],pos[N_MAX];
	T val[N_MAX];

	void sift_up(int i,const T &x){
		val[i]=x;
		while(i!=0 && val[(i-1)/d]>val[i]){
			int p=(i-1)/d;
			swap(pos[key[p]],pos[key[i]]);
			swap(key[p],key[i]);
			swap(val[p],val[i]);
			i=p;
		}
	}
	void sift_down(int i,const T &x){
		val[i]=x;
		for(int j,k,c;;i=j){
			j=i;
			for(c=0,k=d*i+1;c<d;c++,k++) if(k<n && val[j]>val[k]) j=k;
			if(j==i) break;
			swap(pos[key[j]],pos[key[i]]);
			swap(key[j],key[i]);
			swap(val[j],val[i]);
		}
	}
public:
	d_heap_for_Dijkstra(int d):n(0),d(d){}
	int find_min()const{ return key[0]; }
	void insert(int u,const T &x){
		int i=n++;
		key[i]=u;
		pos[u]=i;
		sift_up(i,x);
	}
	void delete_min(){
		n--;
		key[0]=key[n];
		sift_down(0,val[n]);
	}
	void decrease_key(int u,const T &x){
		sift_up(pos[u],x);
	}
	bool empty()const{ return n==0; }
	int size()const{ return n; }
	// bool member(int u)const{ return pos[u]}
	void print(){
		puts("-------");
		printf("n=%d:\n",n);
		rep(i,n) printf("  key[%d] = %d, val[%d] = %d\n",i,key[i],i,val[i]);
		rep(i,5) printf("  pos[%d] = %d\n",i,pos[i]);
		puts("-------");
	}
};

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--;
// printf("s=%d, t=%d\n",s+1,t+1);

			int d[100];
			rep(u,n) d[u]=(u==s?0:INF);
			d_heap_for_Dijkstra<int> H(4);
			H.insert(s,0);
			while(!H.empty()){
// H.print();
				int u=H.find_min();
// printf("  u=%d, d[%d]=%d\n",u,u,d[u]);
				H.delete_min();

				rep(i,G[u].size()){
					const edge &e=G[u][i];
					int d2=d[u]+(type==0?e.cost1:e.cost2);
					if(d[e.v]>d2){
// printf("    v=%d, d2=%d\n",e.v,d2);
						if(d[e.v]==INF) H.insert(e.v,d2);
						else            H.decrease_key(e.v,d2);
						d[e.v]=d2;
					}
				}
			}

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

	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <utility>
#include <vector>

const int INF = 10000000;

using Mat = std::vector< std::vector<int> >;

void wf(Mat& adj_mat) {
  int n = adj_mat.size();

  for(int i = 0; i < n; ++i) {     // via node
    for(int j = 0; j < n; ++j) {   // start
      for(int k = 0; k < n; ++k) { // terminal
        adj_mat[j][k] = std::min(adj_mat[j][k], adj_mat[j][i] + adj_mat[i][k]);
      }
    }
  }
}

void answer(int p, int q, int r) {
}

int main() {
  int n, m;
  int a, b, cost, time;

  std::cin >> n >> m;
  std::vector<std::vector<int> > cost_table, time_table;
  cost_table.resize(m);
  time_table.resize(m);
  for(int i = 0; i < m; ++i) {
    cost_table.at(i).resize(m);
    time_table.at(i).resize(m);
    for(int j = 0; j < m; ++j){
      cost_table[i][j] = INF;
      time_table[i][j] = INF;
    }
  }

  for(int i = 0; i < n; ++i){
    std::cin >> a >> b >> cost >> time;
    --a, --b;
    cost_table[a][b] = cost_table[b][a] = cost;
    time_table[a][b] = time_table[b][a] = time;
  }

  wf(cost_table);
  wf(time_table);

  // Query
  int k;
  int p, q, r;
  std::cin >> k;
  for(int i = 0; i < k; ++i){
    std::cin >> p >> q >> r;
    --p, --q;
    if (r == 0)
      std::cout << cost_table[p][q] << std::endl;
    else
      std::cout << time_table[p][q] << std::endl;

  }
}

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

using namespace std;

int main(void){
	int floy[101][101][2];
	while(1){
		int n,m;
		scanf("%d%d",&n,&m);
		if(n==0&&m==0){
			break;
		}
			
		for(int b=0;b<2;b++){
			for(int i=0;i<=m;i++){
				for(int j=0;j<=m;j++){
					floy[i][j][b]=1<<29;
				}
			}
		}
		
		for(int i=0;i<n;i++){
			int a,b,cost,time;
			scanf("%d%d%d%d",&a,&b,&cost,&time);
			floy[a][b][0]=cost;
			floy[b][a][0]=cost;
			floy[a][b][1]=time;
			floy[b][a][1]=time;
		}
		
		for(int b=0;b<2;b++){
			for(int k=1;k<=m;k++){
				for(int i=1;i<=m;i++){
					for(int j=1;j<=m;j++){
							floy[i][j][b]=min(floy[i][j][b],floy[i][k][b]+floy[k][j][b]);
					}
				}
			}
		}
		
		
		int kazu;
		scanf("%d",&kazu);
		
		for(int i=0;i<kazu;i++){
			int a,b,c;
			scanf("%d%d%d",&a,&b,&c);
			printf("%d\n",floy[a][b][c]);
		}
	}
}

C++: #include<iostream>

using namespace std;

int main(){
  int n,m,x,y,cost,time,p,q,r;
  while(true){
    cin >> n >> m;
    if(n+m == 0)break;
    int matrix1[n+2][n+2],matrix2[n+2][n+2];
    for(int i=0;i<n+2;i++){
      for(int j=0;j<n+2;j++){
	matrix2[i][j] = matrix1[i][j] = 1000000;
      }
    }
    for(int i=0;i<n;i++){
      cin >> x >> y >> cost >> time;
      matrix1[x][y] = matrix1[y][x] = cost;
      matrix2[y][x] = matrix2[x][y] = time;
    }
    for(int k=1;k<=n;k++){
      for(int i=1;i<=n;i++){
	for(int j=1;j<=n;j++){
	  matrix1[i][j] = min(matrix1[i][j],matrix1[i][k]+matrix1[k][j]);
	  matrix2[i][j] = min(matrix2[i][j],matrix2[i][k]+matrix2[k][j]);

	}
      }
    }


    int k;
    cin >> k;
    for(int i=0;i<k;i++){
      cin >> p >> q >> r;
      if(r == 0){
	cout << matrix1[p][q] << endl;
      }
      else{
	cout << matrix2[p][q] << endl;
      }

    }

  }
  return 0;
}