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<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<stack>
#include<cmath>
using namespace std;

const double EPS = 1e-4;

struct Building{
	int x, y;
};

struct Edge{
	int to;
	double cost;
	Edge(){}
	Edge(const int &_to, const double &_cost){
		to = _to; cost = _cost;
	}
};

struct Data{
	int n;
	double cost;
	Data(){}
	Data(const int &_n, const double &_cost){
		n = _n; cost = _cost;
	}
	bool operator < (const Data &a) const{
		return cost > a.cost;
	}
};

double GetDistance(Building &b1, Building &b2){
	double dx = b1.x - b2.x, dy = b1.y - b2.y;
	return sqrt(dx*dx + dy*dy);
}

int main(){
	int N, M, B, S, G;

	while(cin >> N, N){
		Building v[1000];
		vector<Edge> e[1000];

		for(int i = 0; i < N; i++){
			cin >> B; B--;
			cin >> v[B].x >> v[B].y;
		}

		for(int i = 0; i < N; i++){
			for(int j = i+1; j < N; j++){
				double dist = GetDistance(v[i], v[j]);
				if(dist <= 50){
					e[i].push_back( Edge(j, dist) );
					e[j].push_back( Edge(i, dist) );
				}
			}
		}

		cin >> M;
		for(int j = 0; j < M; j++){
			cin >> S >> G; S--; G--;

			priority_queue<Data> pq;
			Data pq_top;
			pq.push( Data(S, 0) );
			double memo[1000];
			fill_n(memo, N, -1);
			bool na = true;

			while( !pq.empty() ){
				pq_top = pq.top(); pq.pop();
			
				if(memo[pq_top.n] > -0.5) continue;
				memo[pq_top.n] = pq_top.cost;
				if(pq_top.n == G){
					na = false; break;
				}

				for(int i = 0; i < e[pq_top.n].size(); i++){
					pq.push( Data( e[pq_top.n][i].to, pq_top.cost + e[pq_top.n][i].cost ) );
				}
			}

			if(na){
				puts("NA"); break;
			}

			stack<int> ans;
			while(true){
				ans.push(G);
				if(G == S) break;
				for(int i = 0; i < e[G].size(); i++){
					if( abs(memo[G] - memo[ e[G][i].to ] - e[G][i].cost) < EPS){
						G = e[G][i].to; break;
					}
				}
			}
		
			printf("%d", ans.top()+1 ); ans.pop();
			while( !ans.empty() ){
				printf(" %d", ans.top()+1 ); ans.pop();
			}puts("");
		}
	}
	return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <vector>
#include <list>
#include <cmath>
#include <fstream>
#include <algorithm>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <complex>
#include <iterator>
#include <cstdlib>
#include <sstream>

using namespace std;

#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) (EQ((a).real(),(b).real()) && EQ((a).imag(),(b).imag()))

typedef long long ll;

const int MAX_SIZE = 10000;

struct edge{
	int to;
	double cost;
};

typedef pair<double,int> P;
int V;

const int MAX_V = 5000;

vector<edge> G[MAX_V];
double d[MAX_V];
const int INF = 1000000000;

int prevv[MAX_V];

void dijkstra(int s){
	priority_queue<P,vector<P>,greater<P> > que;
	fill(d,d+MAX_V,INF);
	fill(prevv,prevv+MAX_V,-1);
	d[s] = 0;
	que.push(P(0,s));
	while(!que.empty()){
		P p = que.top();
		que.pop();
		int v = p.second;
		if(d[v] < p.first)
			continue;
		for(int i = 0; i < G[v].size(); i++){
			if(v==6){
//				cout<<endl;
			}
			edge e = G[v][i];
			if(d[e.to] > d[v] + e.cost){
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to],e.to));
				// »Ìm[hÖÌÅZ£oHðL^µÄ¨­
				prevv[e.to] = v;
			}
		}
	}
}

class Building{
public:
	int node;
	int x;
	int y;
};


int main(){

	int n;
	while(cin>>n&&n!=0){
		vector<Building> vb;
		for(int i = 0; i < n; i++){
			Building b;
			cin>>b.node>>b.x>>b.y;
			vb.push_back(b);
		}
		// »ê¼êÌgÝí¹ÉÎµÄµç×é
		for(int i = 0; i < vb.size(); i++){
			for(int j = i+1; j < vb.size(); j++){
				int dist = (vb[i].x-vb[j].x)*(vb[i].x-vb[j].x)+(vb[i].y-vb[j].y)*(vb[i].y-vb[j].y);
				// rÔÌ£Ìñæª2500Èº¾Á½êAGbWðÞ·Ô
				if(!(sqrt((double)dist)>50)){
					edge e;
					e.cost=sqrt((double)dist);
					e.to=vb[j].node;
					G[vb[i].node].push_back(e);

					e.cost=dist;
					e.to=vb[i].node;
					G[vb[j].node].push_back(e);
				}
			}
		}

		//dijkstra(1);
		//cout<<d[22]<<endl;

		int m;
		cin>>m;
		for(int i = 0; i < m; i++){
			int s,g;
			cin>>s>>g;
			dijkstra(s);
			if(d[g]==INF)
				cout<<"NA"<<endl;
			else{
			//	cout<<d[g]<<endl;
				vector<int> path;
				path.push_back(g);
				int cp=g;
				while(1){
					int np=prevv[cp];
					cp=np;
					path.push_back(cp);
					if(cp==s)
						break;
				}
				for(int j = 0; j < path.size(); j++){
					cout<<path[path.size()-1-j];
					if(j==path.size()-1)
						cout<<endl;
					else
						cout<<" ";
				}
			}
		}
		for(int i = 0; i < MAX_V; i++)
			G[i].clear();
	}

	return 0;
}