Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"strings"
	"math"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	dd := make([][]int, 1000)
	for i := range dd {
		dd[i] = make([]int, 1000)
	}
	num := make([]int,1000)
	inv := make([]int, 1001)
	x := make([]int, 1000)
	y := make([]int, 1000)
	vv := make([]int, 1000)
	nowt := make([]float64, 1000)
	rev := make([]int, 1000)
	for scanner.Scan() {
		n, _ := strconv.Atoi(scanner.Text())
		if n == 0 {
			break
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf1 := strings.Split(scanner.Text(), " ")
			num[i], _ = strconv.Atoi(buf1[0])
			x[i], _ = strconv.Atoi(buf1[1])
			y[i], _ = strconv.Atoi(buf1[2])
			inv[num[i]] = i
		}
		for i := 0; i < n; i++ {
			for j := 0; j < n; j++ {
				dd[i][j]=(x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j])
			}
		}
		scanner.Scan()
		m, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < m; i++ {
			scanner.Scan()
			buf2 := strings.Split(scanner.Text(), " ")
			c, _ := strconv.Atoi(buf2[0])
			d, _ := strconv.Atoi(buf2[1])
			c = inv[c]
			d = inv[d]
			for j := 0; j < n; j++ {
				vv[j] = 0
				nowt[j]=999999999
				rev[j]=-1
			}
			nowt[c]=0
			for j := 0; j < n; j++ {
				M := 99999999
				at := 0
				for k := 0; k < n; k++ {
					if vv[k] == 0 && float64(M) > nowt[k] {
						M=int(nowt[k])
						at = k
					}
				}
				if M > 90000000 {
					break
				}
				vv[at]=1
				for k := 0; k < n; k++ {
					if vv[k] == 0 && dd[at][k]<=2500&&nowt[k]>nowt[at]+math.Sqrt(float64(dd[at][k])) {
						nowt[k]=nowt[at]+math.Sqrt(float64(dd[at][k]))
						rev[k] = at
					}
				}
			}
			if vv[d] == 0 {
				fmt.Println("NA")
			} else {
				stack := make([]int, 0)
				V := d
				for V != c {
					stack = append(stack, V)
					V = rev[V]
				}
				fmt.Print(num[c])
				for len(stack) > 0 {
					fmt.Printf(" %d", num[stack[len(stack)-1]])
					stack = stack[:len(stack)-1]
				}
				fmt.Println()
			}
		}
	}
}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <utility>
#include <queue>
#include <cmath>

const int INF = 1000000;
using namespace std;

void sub(vector<vector<double> >edge,int s,int g){
    vector<double> kyori(edge.size());
    for(int i=0;i<kyori.size();i++)kyori[i]=INF;
    kyori[s] = 0;
    priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > > q;
    q.push(make_pair(s,0));
    while(!q.empty()){
        pair<int,int> p = q.top();q.pop();

        if(kyori[p.first] < p.second) continue;
        for(int i=0;i<edge.size();i++){
            if(kyori[i] > kyori[p.first]+edge[p.first][i]){
                kyori[i] = kyori[p.first]+edge[p.first][i];
                q.push(make_pair(i,kyori[i]));
            }
        }
    }
    if(kyori[g] == INF){
        cout << "NA" << endl;
        return ;
    }else{
        int u = g;
        vector<int> prev;
        prev.push_back(u);
        while(u!=s){
            for(int i=0;i<edge.size();i++){
                if(i==u)continue;
                if(abs(kyori[u]-(kyori[i]+edge[i][u])) < 1){
                    u = i;
                    prev.push_back(u);
                    break;
                }
            }
        }
        for(int i=prev.size()-1;i>-1;i--){
            cout << prev[i] << " ";
        }
        cout << endl;

    }
}
void solve(int n){
    vector<pair<int,int> > v(1001);
    vector<vector<double> > edge(v.size(),vector<double>(v.size()));
    for(int i=0;i<v.size();i++){
        v[i] = make_pair(INF,INF);
    }
    for(int i=0;i<n;i++){
        int b,x,y;
        cin >> b >> x >> y;
        v[b] = make_pair(x,y);
    }
    for(int i=0;i<v.size();i++){
        for(int j=0;j<v.size();j++){
            if((v[i].first == INF && v[i].second==INF) ||
               (v[j].first == INF && v[j].second==INF)){
                edge[i][j] = INF;
            }else{
                double len = sqrt((v[i].first-v[j].first)*(v[i].first-v[j].first)+
                                  (v[i].second-v[j].second)*(v[i].second-v[j].second));
                if(len > 50){
                    edge[i][j] = INF;
                }else{
                    edge[i][j] = len;
                }
            }
        }
    }
    int m;
    cin >> m;
    for(int i=0;i<m;i++){
        int s,g;
        cin >> s >> g;
        sub(edge,s,g);
    }
}
int main(){
    while(true){
        int n;
        cin >> n;
        if(n==0)break;
        solve(n);
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	while(cin >> n , n){
		int g[n][n];
		for(int i = 0; i < n; i++)
			for(int j = 0; j < n; j++)
				g[i][j] = 100000000;
		int b[n] , x[n] , y[n];
		for(int i = 0; i < n; i++)
			cin >> b[i] >> x[i] >> y[i];
		for(int i = 0; i < n; i++)
			for(int j = 0; j < n; j++){
				int xx = x[i] - x[j],
					   yy = y[i] - y[j];
				if(pow(xx , 2) + pow(yy , 2) <= 2500 && i != j)
					g[i][j] = g[j][i] = 1;
			}
		int m;
		cin >> m;
		int s , go;
		for(int i = 0; i < m; i++){
			cin >> s >> go;
			s--; go--;
			vector <int> used(n,false);
			vector <int> gone(n,false);
			vector <int> dist(n,100000000);
			dist[s] = 0;
			gone[s] = 0;
			while(1){
				int va = -1;
				for(int j = 0; j < n; j++)
					if(used[j] == false && (va == -1 || dist[va] > dist[j]))
						va = j;
				if(va == -1)
					break;
				used[va] = true;
				for(int j = 0; j < n; j++){
					if(dist[j] >= dist[va] + g[va][j])
						gone[j] = va;
					dist[j] = min(dist[j] , dist[va] + g[va][j]);
				}
			}
			if(dist[go] == 100000000)
				cout << "NA" << endl;
			else{
				int kari = go;  // go == 21
				stack <int> out;
				while(1){
					out.push(gone[kari] + 1);
					kari = gone[kari];
					if(kari == s)
						break;
				}
				while(!out.empty()){
					cout << out.top() << " ";
					out.pop();
				}
				cout << go + 1 << endl;
			}
		}
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef complex<double> P;
int N,M;
vector<P> ps;
const int INF = (1<<29);

struct state {
  double c;
  int id;
  state(){}
  state(double c,int id):c(c),id(id){}
  bool operator<(const state& st) const{
    return c > st.c;
  }
};

bool check( P a, P b ){
  return abs( a - b ) <= 50.0;
}

void dijk(int s,int g){
  priority_queue<state> q;
  vector<double> H(N,1e20);
  vector<int> R(N,-1);
  q.push( state(0,s) );
  H[s] = 0.0;
  R[s] = -1;
  while( !q.empty() ){
    state p = q.top(); q.pop();
    for(int to=0;to<N;to++){
      if( check( ps[p.id], ps[to] ) ){
        double nc = p.c + abs( ps[ p.id ] - ps[ to ] );
        if( H[ to ] > nc ){
          H[ to ] = nc;
          R[ to ] = p.id;
          q.push( state( nc, to ) );
        }
      }
    }
  }
  vector<int> ret;
  if( H[ g ] >= INF/10.0 ) {
    cout << "NA" << endl; return;
  }
  for( int i = g; i != -1; i=R[i] ) 
    ret.push_back( i );
  
  reverse( ret.begin(), ret.end() );
  for( int i=0;i<(int)ret.size();i++ ){
    if( i ) cout << " ";
    cout << ret[i]+1;
  }
  cout << endl;
}

int main(){
  while( cin >> N && N ) {
    ps = vector<P>(N);
    for(int i=0;i<N;i++){
      int b,x,y; cin >> b >> x >> y; --b;
      ps[b] = P(x,y);
    }
    cin >> M;
    for(int i=0;i<M;i++){
      int s,g; cin >> s >> g; --s; --g;
      dijk( s, g );
    }
  }
}