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>
#define INF 1e+9
#define EPS 1e-9
using namespace std;

int main(){
	int n,b[100];
	double x[100],y[100];
	int cost[100][100],next[100][100];
	while(cin >> n,n){
		for(int i = 0;i < n;i++){
			for(int j = 0;j < n;j++) {
				cost[i][j] = INF;
				next[i][j] = j;
			}
			cost[i][i] = 0;
		}
		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++){
				if((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]) <= 2500.0 + EPS){
					cost[i][j] = 1;
					cost[j][i] = 1;
				}
			}
		}
		for(int k = 0;k < n;k++){
			for(int i = 0;i < n;i++){
				for(int j = 0;j < n;j++){
					if(cost[i][j] > cost[i][k] + cost[k][j]){
						cost[i][j] = cost[i][k] + cost[k][j];
						next[i][j] = next[i][k];
					}
				}
			}
		}
		int m;
		cin >> m;
		for(int i = 0;i < m;i++){
			int s,g,S,G;
			cin >> s >> g;
			for(int j = 0;j < n;j++){
				if(b[j] == s) S = j;
				if(b[j] == g) G = j;
			}
			if(cost[S][G] == INF){
				cout << "NA" << endl;
				continue;
			}
			while(S != G){
				cout << b[S] << " ";
				S = next[S][G];
			}
			cout << b[G] << endl;
		}
	}
	
	return 0;
}

C++: #include<iostream>
#include<cstring>
#include<algorithm>
#include<math.h>
#include<vector>

using namespace std;

double MapData[101][101];
int XbyId[101], YbyId[101], N;
vector<int> Path;

const int INF = 1000000;


void Init() {
	for (int i = 0; i < 100; i++) {
		XbyId[i] = YbyId[i] = INF;
		for (int j = 0; j < 100; j++) {
			MapData[i][j] = INF;
		}
	}
}

void createMap() {
	double dis;

	for (int i = 0; i < 100; i++) {
		for (int j = 0; j < 100; j++) {
			if (i == j || XbyId[i] == INF || XbyId[j] == INF) {
				continue;
			}
			dis = sqrt( pow(XbyId[i]-XbyId[j], 2) + pow(YbyId[i]-YbyId[j], 2) );
			if (dis > 50) {
				continue;
			}
			MapData[i][j] = dis;
		}
	}
}

void solve(int start, int end) {
	double dist[100];
	bool used[100];
	int preNode[100], current;

	fill(dist, dist + N, INF);
	fill(used, used + N, false);
	fill(preNode, preNode + N, -1);
	dist[start] = 0;

	while (true) {
		current = -1;

		for (int i = 0; i < N; i++) {
			if (!used[i] && (current == -1 || dist[i] < dist[current])) {
				current = i;
			}
		}
		if (current == -1) {
			break;
		}
		used[current] = true;

		for (int next = 0; next < N; next++) {
			if (dist[next] > dist[current] + MapData[current][next]) {
				dist[next] = dist[current] + MapData[current][next];
				preNode[next] = current;
			}
		}
	}

	if (dist[end] == INF) {
		cout << "NA";
		return;
	}

	current = end;
	while (current != -1) {
		Path.push_back(current);
		current = preNode[current];
	}
	reverse(Path.begin(), Path.end());
}

int main() {
	int m,start,end;

	while (cin >> N, N) {
		Init();
		for (int i = 0; i < N; i++) {
			cin >> m;
			--m;
			cin >> XbyId[m] >> YbyId[m];
		}
		createMap();

		cin >> m;
		for (int i = 0; i < m; i++) {
			cin >> start >> end;
			Path.clear();
			solve(--start, --end);
			for (int i = 0; i < Path.size(); i++) {
				cout << Path[i] + 1;
				if (i != Path.size()-1) {
					cout << " ";
				}
			}
			cout << endl;
		}
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define rep(i,n) for(i=0;i<n;++i)
#define each(itr,c) for(__typeof(c.begin()) itr=c.begin(); itr!=c.end(); ++itr)
#define mp make_pair
#define pb push_back
#define fi first
#define sc second

struct building{ int b,x,y; };
struct edge{ int to; long cost; };
typedef pair<int,int> pi;

const long INF=(1L<<50);

long dist2(building A, building B)
{
	return (long)(A.x-B.x)*(A.x-B.x)+(long)(A.y-B.y)*(A.y-B.y);
}

int main()
{
	int i,j;
	while(1)
	{
		int n;
		cin >>n;
		if(n==0) break;

		vector<building> v(n);
		rep(i,n)
		{
			scanf(" %d %d %d",&v[i].b,&v[i].x,&v[i].y);
			--v[i].b;
		}

		//be connected?
		vector<edge> G[1000];
		rep(i,n)rep(j,i)
		{
			if(dist2(v[i],v[j])<=50*50)
			{
				//printf("push %d %d -> %ld\n",v[i].b+1,v[j].b+1,dist2(v[i],v[j]));
				G[v[i].b].pb(edge{v[j].b,dist2(v[i],v[j])});
				G[v[j].b].pb(edge{v[i].b,dist2(v[i],v[j])});
			}
		}

		int m;
		cin >>m;
		rep(i,m)
		{
			int s,g;
			scanf(" %d %d",&s,&g);
			--s;
			--g;

			long dist[1000];
			fill(dist,dist+1000,INF);
			dist[s]=0;
			int par[1000];
			fill(par,par+1000,-1);

			//dijkstra
			priority_queue<pi,vector<pi>,greater<pi>> que;
			que.push(pi(0,s));
			while(!que.empty())
			{
				pi p=que.top();
				que.pop();
				int v=p.sc;
				if(dist[v]<p.fi) continue;

				rep(j,(int)G[v].size())
				{
					edge e=G[v][j];
					if(dist[e.to]>dist[v]+e.cost)
					{
						//printf("%d -> %d\n",v,G[v][j]);
						dist[e.to]=dist[v]+e.cost;
						/*
						printf("dist[%d]=%ld\n",e.to+1,dist[e.to]);
						printf("update par %d = %d\n",e.to+1,v+1);
						*/
						par[e.to]=v;
						que.push(pi(dist[e.to],e.to));
					}
				}
			}

			//search parent
			vector<int> ans;
			ans.pb(g+1);
			int now=g;
			while(par[now]!=-1)
			{
				ans.pb(par[now]+1);
				now=par[now];
			}

			reverse(ans.begin(),ans.end());

			//output
			if(ans[0]!=s+1) printf("NA\n");
			else
			{
				rep(j,(int)ans.size())
				{
					if(j) printf(" ");
					printf("%d", ans[j]);
				}
				printf("\n");
			}
		}

	}
}