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 <cmath>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cstdlib>
#include <ctime>
using namespace std;

#define rep(i, n) for(int i = 0; i < n; i++)
typedef pair<double, int> state;

double memo[100];
int pre[100];
int name[100];
double x[100];
double y[100];

map<int, int> nums;

double dis(int i, int j){
  return sqrt((x[i] - x[j])*(x[i] - x[j]) + (y[i] - y[j])*(y[i] - y[j]));
}

int main(){
  int n, m;
  int b;
  int s, g;
  while(cin >> n &&n){
    nums.clear();
    rep(i, n){
      cin >> b >> x[i] >> y[i];
      name[i] = b;
      nums[b] = i;
    }
    cin >> m;
    rep(i, m){
      memset(pre, -1, sizeof(pre));
      fill(memo, memo + 100, 1e10);
      cin >> s >> g;
      memo[nums[s]] = 0;
      priority_queue<state, vector<state>, greater<state> > que;
      que.push(state(0, nums[s]));
      while(!que.empty()){
	state st = que.top();
	que.pop();
	int v = st.second;
	double cost = st.first;
	if(name[v] == g){
	  break;
	}
	if(cost > memo[v]) continue;
	rep(i, n){
	  double d = dis(v, i);
	  if(d > 50.0) continue;
	  if(memo[i] > memo[v] + d){
	    memo[i] = memo[v] + d;
	    pre[i] = v;
	    que.push(state(memo[i], i));
	  }
	}
      }
      if(pre[nums[g]] == -1 && s != g){
	cout << "NA" << endl;
      }else{
	vector<int> res;
	int v = nums[g];
	res.push_back(v);
	while(pre[v] >= 0){
	  v = pre[v];
	  res.push_back(v);
	}
	rep(i, (int)res.size()){
	  if(i != 0) cout << " " ;
	  cout << name[res[res.size() - 1 - i]];
	}
	cout << endl;
      }
    }
  }
  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cmath>
using namespace std;

#define MAX 1100
#define INF (1<<29)
#define EPS 1e-9

struct Point{
  int x, y, id;
};

vector<Point> bill;
double dist[MAX][MAX];
int prev[MAX];
int V;

void init(){
  bill.clear();
  for(int i = 0 ; i < MAX ; i++){
    for(int j = 0 ; j < MAX ; j++){
      dist[i][j] = INF;
      if(i == j) dist[i][j] = 0;
    }
  }
}

void dijkstra(int s){
  int d[MAX];
  bool used[MAX];
  fill(d, d+MAX, INF);
  fill(used, used+MAX, false);
  fill(prev, prev+MAX, -1);
  d[s] = 0;
  
  while(true){
    int v = -1;
    for(int u = 0 ; u < V ; u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }
    if(v == -1) break;
    used[v] = true;
    
    for(int u = 0 ; u < V ; u++){
      if(d[u] > d[v] + dist[v][u]){
	d[u] = d[v] + dist[v][u];
	prev[u] = v;
      }
    }
  }
}

vector<int> get_path(int t){
  vector<int> path;
  for(; t != -1 ; t = prev[t]) path.push_back(t);
  reverse(path.begin(), path.end());
  return path;
}

double getDist(int from, int to){
  double ret = sqrt( ((bill[from].x - bill[to].x)*(bill[from].x - bill[to].x)) +
		     ((bill[from].y - bill[to].y)*(bill[from].y - bill[to].y)) );
  return ret;
}
  
int main(){
  while(cin >> V, V){
    init();
    Point p;
    for(int i = 0 ; i < V ; i++){
      cin >> p.id >> p.x >> p.y;
      p.id--;
      bill.push_back(p);
    }
    
    for(int i = 0 ; i < V ; i++){
      for(int j= 0 ; j < V ; j++){
	double dis = getDist(bill[i].id, bill[j].id);
	//if(dis >= 50 + EPS) continue;
	if(dis <= 50 + EPS){
	dist[bill[i].id][bill[j].id] = dist[bill[j].id][bill[i].id] = dis;
	}
      }
    }
    int m;    
    cin >> m;
    int s, g;
    while(m--){
      cin >> s >> g;
      s--, g--;
      dijkstra(s);
      vector<int> ans_path = get_path(g);
      if(ans_path.size() <= 1) cout << "NA" << endl;
      else{
	for(int i = 0 ; i < (int)ans_path.size() ; i++){
	  //if(i == (int)ans_path.size()-1) cout << ans_path[i]+1 << endl;
	  cout << ans_path[i]+1 << ' ';
	}
	cout << endl;
      }
    } 
  }
  return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <string>
#include <cmath>
#define INF (1<<21)
using namespace std;

int main(){
  int i,j,n,m,a[1001],x[1001],y[1001],s,g,cost,f[1001],pi[1001],pj[1001],p,sum;
  double G[1001][1001],d[1001],min;
  while(1){
    cin >> n;
    if(n == 0) break;
    for(i=0;i<n;i++){
      for(j=0;j<n;j++){
	G[i][j] = INF;
      }
    }

    for(i=0;i<n;i++){
      cin >> a[i] >> x[i] >> y[i];
    }

    for(i=0;i<n;i++){
      for(j=i+1;j<n;j++){
	if(sqrt( pow((double)x[i] - x[j],2) + pow((double)y[i] - y[j],2)) <= 50.0) G[i][j] = G[j][i] = sqrt( pow((double)x[i] - x[j],2) + pow((double)y[i] - y[j],2));
      }
    }

    cin >> m;
    for(int k=0;k<m;k++){ 
      
      cin >> s >> g;
      for(i=0;i<n;i++){
	if(a[i] == s) s = i;
	else if(a[i] == g) g = i;
      }

      for(i=0;i<n;i++){
	d[i] = INF;
	f[i] = 0;
      }
      
      d[s] = 0;
      while(1){
	min = INF;
	for(i=0;i<n;i++){
	  if(d[i]<min && f[i] == 0){
	    min = d[i];
	    p = i;
	  }
	}
	if(min == INF) break;
	f[p] = 1;
	for(i=0;i<n;i++){
	  if(f[i] == 1) continue;
	  if(G[p][i] + d[p]< d[i]){
	    d[i] = G[p][i] + d[p];
	    pi[i] = p;
	  }
	}
      }

      if(d[g] == INF) cout << "NA";
      else{
	pi[s] = -1;
	cout << a[s];
	for(i = 0; g != -1; g = pi[g]){
	  pj[i] = g;
	  i++;
	}
	for(j = i - 2; j >= 0; j--) cout << " " << a[pj[j]];
      }
      cout << endl;

    }
  }
  return 0;
}