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 <algorithm>
#include <cmath>
#include <vector>

struct bill{int n, x, y;};

double len[1001][1001], dist[1001];
int used[1001], prev[1001];
const double INF = 10000000;

std::vector<int> dijkstra(int s, int e){
	std::fill(dist, dist+1001, INF);
	std::fill(prev, prev+1001, 0);

	dist[s] = 0;
	while(1){
		int v = -1;
		for(int u=1;u<1001;u++){
			if(!used[u] && (v==-1 || dist[u]<dist[v]))v=u;
		}
		if(v == -1)break;
		used[v] = 1;
		for(int u=1;u<1001;u++){
			if(dist[u] > dist[v]+len[v][u])
				dist[u] = dist[v]+len[v][u], prev[u] = v;
		}
	}
	std::vector<int> res;
	if(dist[e] == INF)res.push_back(-1);
	else{
		res.push_back(e);
		int v = e;
		while(v != s){
			v = prev[v];
			res.push_back(v);
		}
		std::reverse(res.begin(), res.end());
		return res;
	}
}


int main(){
	int n;
	while(std::cin >> n, n){
		std::fill(used, used+1001, 1);
		for(int i=1;i<1001;i++)
		 	for(int j=1;j<1001;j++)
		 		len[i][j] = INF;

		std::vector<bill> bs;
		for(int i=n;i;i--){
			bill b;
			std::cin >> b.n >> b.x >> b.y;
			used[b.n] = 0;
			bs.push_back(b);
		}

		for(int i=0;i<bs.size()-1;i++){
			for(int j=i+1;j<bs.size();j++){
				double x = bs[i].x-bs[j].x, y = bs[i].y-bs[j].y, dist = sqrt(x*x+y*y);
				if(dist <= 50){
					len[bs[i].n][bs[j].n] = dist;
					len[bs[j].n][bs[i].n] = dist;
				}
			}
		}

		int m;
		std::cin >> m;
		for(;m;m--){
			int start, end;
			std::cin >> start >> end;
			std::vector<int> res = dijkstra(start, end);
			if(res[0] == -1)std::cout << "NA\n";
			else{
				for(int i=0;i<res.size();i++){
					std::cout << res[i] << (i+1-res.size()?" ":"\n");
				}
			}
		}
	}
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <climits>
#include <queue>
using namespace std;

typedef pair<double,int> P;

const double INF = 1000000000;
struct edge { int to; double cost; };
vector<edge> G[1001];

void solve(int s, int g) {
    double d[1001]; fill(d, d+1001, INF);
    int prv[1001]; fill(prv, prv+1001, -1);
    priority_queue<P, vector<P>, greater<P>> q;
    d[s] = 0;
    q.push(make_pair(0, s));
    while ( ! q.empty()) {
        int v = q.top().second;
        q.pop();
        for (int i=0; i<(int)G[v].size(); ++i) {
            edge &e = G[v][i];
            if (e.cost != INF && d[v] + e.cost < d[e.to]) {
                d[e.to] = d[v] + e.cost;
                q.push(make_pair(d[e.to], e.to));
                prv[e.to] = v;
            }
        }
    }
    int k = g;
    if (prv[k] < 0) {
        cout << "NA" << endl;
    } else {
        vector<int> ret;
        while (0 <= k) {
            ret.push_back(k);
            k = prv[k];
        }
        for (int i=ret.size()-1; i>=0; --i) {
            cout << ret[i] << (i != 0 ? " " : "");
        }
        cout << endl;
    }
}

int main() {
    int n, m, s, g;
    int b[1000], x[1000], y[1000];
    while (cin >> n, n) {
        for (int i=0; i<n; ++i) {
            cin >> b[i] >> x[i] >> y[i];
        }
        for (int i=0; i<1001; ++i) {
            G[i].clear();
        }
        for (int i=0; i<n; ++i) {
            for (int j=i+1; j<n; ++j) {
                int cost = (x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]);
                if (2500 < cost) {
                    G[b[i]].push_back((edge){b[j], INF});
                    G[b[j]].push_back((edge){b[i], INF});
                } else {
                    G[b[i]].push_back((edge){b[j], sqrt(cost)});
                    G[b[j]].push_back((edge){b[i], sqrt(cost)});
                }
            }
        }
        cin >> m;
        for (int i=0; i<m; ++i) {
            cin >> s >> g;
            solve(s, g);
        }
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define INF 1e9
using namespace std;
typedef double ll;
typedef pair<double,int> P;
int n;
ll G[101][101];

void dijkstra(int s,int g){
  ll D[101];
  int from[101];
  for(int i=0;i<101;i++) D[i]=INF;
  priority_queue<P,vector<P>,greater<P> > Q;
  D[s]=0;
  Q.push(P(0,s));

  while(!Q.empty()){
    P t=Q.top(); Q.pop();
    int pos=t.second;
    ll cost=t.first;
    if(pos==g) break;
    if(D[pos]<cost) continue;
    
    for(int i=0;i<n;i++){
      if(G[pos][i]==-1||i==pos)continue;
      if(cost+G[pos][i]<D[i]){
	Q.push(P(cost+G[pos][i],i));
	D[i]=cost+G[pos][i];
	from[i]=pos;
      }
    }
  }

  if(D[g]==INF){cout<<"NA"<<endl;return;}
    
  vector<int> res;
  res.push_back(g);
  int pos=g;
  while(pos!=s){
    pos=from[pos];
    res.push_back(pos);
  }

  for(int i=0;i<res.size();i++){
    if(i) cout<<" ";
    cout<<res[res.size()-1-i]+1;
  }
  cout<<endl;
}


int main(){
  while(cin>>n,n){
    ll x[101],y[101];
    for(int i=0;i<n;i++){
      int b;
      cin>>b;
      cin>>x[b-1]>>y[b-1];
    }
    
    for(int i=0;i<n;i++)
      for(int j=i+1;j<n;j++){
	ll X=(x[i]-x[j]);
	ll Y=(y[i]-y[j]);
	ll dis=sqrt(X*X+Y*Y);
	if(dis>50) G[i][j]=G[j][i]=-1;
	else G[i][j]=G[j][i]=dis;
    }

  int m;
  cin>>m;
  while(m--){
    int s,g;
    cin>>s>>g;
    dijkstra(s-1,g-1);
  }
  }
  return 0;
}