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 <vector>
#include <queue>
#include <math.h>

using namespace std;

const int MAX = 1000;

struct int2
{
	int x;
	int y;
};

class Node
{
public:
	int id;
	double cost;
	int parent;
	bool visited;
	vector<int> edge_to;
	vector<double> edge_cost;

	Node() {}
	Node(int id) : id(id), cost(-1.0), parent(-1), visited(false) {}
};

int n, m;
Node nodes[MAX];
int2 pos[MAX];
int sid, gid;

void solve()
{
	queue<Node> q;
	nodes[sid].cost = 0.0;
	q.push(nodes[sid]);
	
	while(!q.empty())
	{
		Node nn = q.front();
		q.pop();
		
		if(nn.visited) continue;
		if(nn.id==gid) return;
		nn.visited = true;
		for(int i=0; i<nn.edge_to.size(); i++)
		{
			int to = nn.edge_to[i];
			double cost = nn.cost + nn.edge_cost[i];
			if(nodes[to].cost > cost || nodes[to].cost < 0.0)
			{
				if(nodes[to].visited) continue;
				nodes[to].cost = cost;
				nodes[to].parent = nn.id;
				q.push(nodes[to]);
			}
		}
	}
}

void reset()
{
	for(int i=0; i<n; i++)
	{
		nodes[i].cost = -1;
		nodes[i].parent = -1;
		nodes[i].visited = false;
	}
}

int main(int argc, char** argv)
{
	int b, x, y;
	while(cin >> n, n)
	{
		for(int i=0; i<n; i++)
		{
			cin >> b >> x >> y;
			int2 tmp = {x, y};
			pos[b-1] = tmp;
			nodes[i] = Node(i);
		}
		
		for(int i=1; i<n; i++)
		{
			for(int j=0; j<i; j++)
			{
				int dx = pos[i].x - pos[j].x;
				int dy = pos[i].y - pos[j].y;
				double dist =  sqrt((double)(dx*dx + dy*dy));
				if(dist <= 50.0)
				{
					nodes[i].edge_to.push_back(j);
					nodes[i].edge_cost.push_back(dist);
					nodes[j].edge_to.push_back(i);
					nodes[j].edge_cost.push_back(dist);
				}
			}
		}
		
		cin >> m;
		
		for(int k=0; k<m; k++)
		{
			cin >> sid >> gid;
			sid = sid - 1;
			gid = gid - 1;
			
			solve();
		
			vector<int> way;
			way.push_back(gid);
			Node nn =nodes[gid];
			while(nn.parent != -1)
			{
				way.push_back(nn.parent);
				nn = nodes[nn.parent];
			}
		
			if(way.size() > 1)
			{
				for(int i=0; i<way.size(); i++)
				{
					if(i!=0) cout <<" ";
					cout << way[way.size() - i -1] + 1;
				}
			}
			else
			{
				cout << "NA";
			}
			cout << endl;
		}
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
struct grid {ll to; ld cost;};
using Graph = vector<vector<grid>>;
using P = pair<ld, ll>;
constexpr ll INF = 1ll<<60;	   
ld distance(ll x1, ll y1, ll x2, ll y2)
{
	return sqrt(pow(x1-x2, 2)+pow(y1-y2, 2));
}

int main(int argc, char **argv)
{
	while (true)
	{
		ll N; cin >> N;
		if (N == 0)break;
		vector<pair<ll, ll>> coo(N);
		vector<ll> id(N);
		for (ll i = 0; i < N; ++i)
		{
			ll x, y; cin >> id[i] >> x >> y;
			coo[i] = P(x, y);
			--id[i];
		}
		
		Graph G(N);
		for (ll i = 0; i < N; ++i)
		{
			for (ll j = 0; j < N; ++j)
			{
				if (id[i] == id[j]) continue;
				ld d = distance(coo[i].first, coo[i].second, coo[j].first, coo[j].second);
				if (d <= 50.0)
				{
					G[id[i]].push_back(grid{id[j], d});
				}
			}
		}

		ll m; cin >> m;
		for (ll _ = 0; _ < m; ++_)
		{
			ll s, g; cin >> s >> g;
			--s, --g;
			priority_queue<P, vector<P>, greater<P>> que;
			que.push(P(0.0, s));
			vector<ld> dist(N, INF);
			dist[s] = 0.0;
			vector<ll> his(5010, -1);
			vector<ll> ans;
			
			while (!que.empty())
			{
				P p = que.top(); que.pop();
				ll now = p.second;
				if (dist[now] < p.first) continue;

				if (now == g)
				{
					ans.push_back(g);
					ll tmp = g;
					while (tmp != s)
					{
						tmp = his[tmp];
						ans.push_back(tmp);
					}
					break;
				}

				for (auto &nv : G[now])
				{
					ld nc = dist[now] + nv.cost;
					if (dist[nv.to] > nc)
					{
						dist[nv.to] = nc;
						que.push(P(dist[nv.to], nv.to));
						his[nv.to] = now;
					}
				}
			}

			// output
			if (ans.empty())
				std::cout << "NA" << std::endl;
			else
			{
				for (ll i = 0; i < ans.size(); ++i)
					std::cout << (i ? " " : "") << ans[ans.size()-1-i]+1;
				std::cout << std::endl;
			}
		}
			
	}
}

C++: #include <iostream>
#include <cmath>
#include <map>
#include <queue>
#include <climits>
#include <algorithm>
using namespace std;
typedef pair<double,double> P;
typedef pair<double,int> NODE;
#define X first
#define Y second
#define DST first
#define POS second
double ecd(P A,P B){
	A.X = fabs(A.X-B.X);
	A.Y = fabs(A.Y-B.Y);
	return sqrt(A.X*A.X+A.Y*A.Y);
}


int main(){
	int n,a,b,m;
	P s,g;
	double x,y;
	while(cin >> n && n){
		map<int,P> coord;
		map<int,int> from;
		map<int,vector< pair<int,double> > > info;
		map<int,double> memo;
		for(int i=0;i<n;i++){
			cin >> a >> x >> y;
			coord[a] = make_pair(x,y);
		}
		
		for(map<int,P>::iterator it1 = coord.begin();it1 != coord.end();it1++){
			for(map<int,P>::iterator it2 = coord.begin();it2 != coord.end();it2++){
				if(ecd((*it1).second,(*it2).second) <= 50.0)
				info[(*it1).first].push_back( make_pair((*it2).first,ecd((*it1).second,(*it2).second)));
			}
			memo[(*it1).first] = (1<<21);
		}

		cin >> m;
		
		for(int i=0;i<m;i++){
			cin >> a >> b;
			vector<int> way;
			priority_queue<NODE,vector<NODE>,greater<NODE> > Q;
			Q.push(make_pair(0,a));
			memo[a]=0;
			from[a]=-1;
			while(Q.size()){
				NODE q = Q.top();Q.pop();
				if(q.POS == b){
					int p = q.POS;
					while(~p){
						way.push_back(p);
						p = from[p];
					}
					break;
				}
				for(int i=0;i<info[q.POS].size();i++){
					if(memo[info[q.POS][i].first] > q.DST + info[q.POS][i].second){
						memo[info[q.POS][i].first] = q.DST + info[q.POS][i].second;
						from[info[q.POS][i].first] = q.POS;
						Q.push(make_pair(memo[info[q.POS][i].first],info[q.POS][i].first));
					}
				}
			}
			if(way.size()){
				reverse(way.begin(),way.end());
				for(int i=0;i<way.size();i++){
					if(i)cout << " ";
					cout << way[i];
				}
			}else{
				cout << "NA";
			}
			cout << endl;
		}
	}
}