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<queue>
#include<vector>
#include<map>
using namespace std;
typedef pair<int,int> P;
typedef struct{
	int next;
	int cost[2];
}edge;

int n,m;
vector<edge> mapp[111];
int bfs(int now,int goal,int k);

int main(){
	while(1){
		cin >> n >> m;
		if(n == 0 && m == 0) break;
		for(int i=0;i<m+1;i++){
			mapp[i].clear();
		}
		for(int i=0;i<n;i++){
			int a,b,cost,tim;
			cin >> a >> b >> cost >> tim;
			edge x;
			x.next = a; x.cost[0] = cost; x.cost[1] = tim;
			mapp[b].push_back(x);
			x.next = b; x.cost[0] = cost; x.cost[1] = tim;
			mapp[a].push_back(x);
		}
		int k;
		cin >> k;
		int ans;
		for(int i=0;i<k;i++){
			int p,q,r;
			cin >> p >> q >> r;
			if(r == 0) ans = bfs(p,q,r);
			else if(r == 1) ans = bfs(p,q,r);
			cout << ans << endl;
		}
	}
}

int bfs(int now,int goal,int k){
	vector<int> min_cost;
	min_cost.resize(m+1,-1);
	priority_queue<P, vector<P>,greater<P> > que;
	que.push(P(0,now));
	min_cost[now] = 0;
	while(!que.empty()){
		P p = que.top(); que.pop();
		int no = p.second;
		int co = p.first;
		if(no == goal) return co;
		if(co > min_cost[no]) continue;
		int len=mapp[no].size();
		for(int i=0;i<len;i++){
			edge x = mapp[no][i];
			if(min_cost[x.next] == -1 || co+x.cost[k]<min_cost[x.next]){
				min_cost[x.next] = co + x.cost[k];
				que.push(P(co+x.cost[k],x.next));
			}
		}
	}
	return min_cost[goal];
}

C++: #include<iostream>
using namespace std;
int main(){
  const int MAX = 1e5;
  for(int n,m;cin>>n>>m,n;){
    int cost[m][m];
    int time[m][m];
    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
	cost[i][j] = MAX;
	time[i][j] = MAX;
      }
    }
    int a,b,c,t;
    for(int i=0;i<n;i++){
      cin>>a>>b>>c>>t;
      cost[max(a-1,b-1)][min(a-1,b-1)] = c;
      time[max(a-1,b-1)][min(a-1,b-1)] = t;
    }
    for(int k=0;k<m;k++){
      for(int i=0;i<m;i++){
	for(int j=0;j<=i;j++){
	  if(cost[i][j]>cost[i][k]+cost[k][j])
	    cost[i][j] = cost[i][k]+cost[k][j];
	  if(time[i][j]>time[i][k]+time[k][j])
	    time[i][j] = time[i][k]+time[k][j];
	}
      }
    }
    int l,r;
    cin>>l;
    for(int i=0;i<l;i++){
      cin>>a>>b>>r;
      if(r)
	cout<<time[max(a-1,b-1)][min(a-1,b-1)]<<endl;
      else
	cout<<cost[max(a-1,b-1)][min(a-1,b-1)]<<endl;      
    }
  }
  return 0;
}

C++: #include<iostream>
#define INF 100000000
using namespace std;
int min(int a,int b){
  return a<b?a:b;
}
int main(){
  int n,m;
  while(cin>>n>>m){
    if(n==0&&m==0) break;
    int d0[m+1][m+1],d1[m+1][m+1];
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
	d0[i][j] = INF;
	d1[i][j] = INF;
      }
    }
    int a,b,cost,time;
    for(int i=0;i<n;i++){
      cin >> a >> b >> cost >> time;
      d0[a][b] = cost;
      d0[b][a] = cost;
      d1[a][b] = time;
      d1[b][a] = time;
    }
    for(int i=1;i<=m;i++){
      for(int j=1;j<=m;j++){
	for(int k=1;k<=m;k++){
	  d0[j][k] = min(d0[j][k],d0[j][i]+d0[i][k]);
	  d1[j][k] = min(d1[j][k],d1[j][i]+d1[i][k]);
	}
      }
    }
    int s,p,q,r; 
    cin >> s;
    for(int i=0;i<s;i++){
      cin >> p >> q >> r;
      if(p==q) cout << 0 << endl;
      else if(r==0) cout << d0[p][q] << endl;
      else cout << d1[p][q] << endl;
    }
  }
  return 0;
}

C++: #include <iostream>

const int INF = 1 << 29;

using namespace std;

int main(void){
	int n,m;
	
	while(cin >> n >> m){
		if((n|m) == 0) break;
		int dist[m][m];
		int time[m][m];
		
		for(int i=0;i<m;i++){
			for(int j=0;j<m;j++){
				if(i == j){
					dist[i][j] = 0;
					time[i][j] = 0;
				}else{
					dist[i][j] = INF;
					time[i][j] = INF;
				}
			}
		}
		
		int s, e, cd, ct;
		for(int i=0;i<n;i++){
			cin >> s >> e >> cd >> ct;
			dist[s-1][e-1] = cd;
			time[s-1][e-1] = ct;
		}
		
		//WF
		for(int k=0;k<m;k++){
			for(int i=0;i<m;i++){
				for(int j=0;j<m;j++){
					dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
					time[i][j] = min(time[i][j], time[i][k] + time[k][j]);
				}
			}
		}
		
		int cases,type;
		cin >> cases;
		for(int i=0;i<cases;i++){
			cin >> s >> e >> type;
			if(type == 0){
				cout << dist[s-1][e-1] << endl;
			}else{
				cout << time[s-1][e-1] << endl;
			}
		}
	}
}