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-6;

struct Building{
	int x, y;
	Building(){
		x = -1; y = -1;
	}
};

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

vector<Edge> e[1000];

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

	while(cin >> N, N){
		Building v[1000];
		for(int i = 0; i < 1000; i++) e[i].clear();

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

		for(int i = 0; i < 1000; i++){
			for(int j = i+1; j < 1000; j++){
				if(v[i].x == -1 || v[j].x == -1 || i == j) continue;
				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, 1000, -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<iostream>
#include<vector>
#include<string>
#include<algorithm>	
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdio>
#include<sstream>
#include<iomanip>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)
using namespace std;
//kaewasuretyuui
typedef long long ll;
typedef pair<double,int> pii;
typedef pair<double,double> pdd;
typedef pair<double,int> pdi;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<pii> vp;
typedef vector<pdd> vdd;
typedef vector<pair<double,int> >vdi;
typedef vector<vp> vvp;
typedef pair<int,pii> pip;
typedef vector<pip>vip	;
const double PI=acos(-1);
const double EPS=1e-8;
const int inf=1e8;
class DIJ{
    public:
    struct edge{
        int to;
        double cost;
    };
    vector<vector<edge> >G;
    int n;
    vector<double> d;//distance
    DIJ(int size){
        n=size;
        G=vector<vector<edge> >(n);
    }
    void add_edge(int a,int b,double c){
        edge e={b,c},ee={a,c};
        G[a].pb(e);
        G[b].pb(ee);
    }
    void dij(int s){
        d=vector<double>(n,inf);
        d[s]=0;
        priority_queue<pii>q;
        q.push(pii(0,s));
        while(!q.empty()){
            pii p=q.top();
            q.pop();
            int pos=p.second;
            double cost=-p.first;
            if(cost>d[pos])continue;
            rep(i,G[pos].size()){
                edge e=G[pos][i];
                int to=e.to;
                double nowcost=cost+e.cost;
                if(nowcost<d[to]){
                    d[to]=nowcost;
                    q.push(pii(-d[to],to));
                }
            }
        }
    }
};
int main(){
    int n;
    while(cin>>n,n){
        vi m(n);
		map<int,int>M;
        vector<pair<int,int> > in(n);
        rep(i,n){
            int a,b,c;
            cin>>a>>b>>c;
            m[i]=a;
			M[a]=i;
            in[i]=pair<int,int>(b,c);
        }
        DIJ dij(n);
        rep(i,n)rep(j,i)if(i!=j&&hypot(in[i].first-in[j].first,in[i].second-in[j].second)<EPS+50)dij.add_edge(i,j,hypot(in[i].first-in[j].first,in[i].second-in[j].second));
        int N;
        cin>>N;
        while(N--){
            int a,b;
            cin>>a>>b;
			a=M[a];b=M[b];
            dij.dij(a);
            if(abs(dij.d[b]-inf)<EPS)cout<<"NA"<<endl;
            else{
                vi out;
                out.pb(b);
                int t=b;
                while(1){
                    rep(i,n)rep(j,dij.G[i].size()){
                        if(t==dij.G[i][j].to&&abs(dij.d[i]+dij.G[i][j].cost-dij.d[t])<EPS){
                            out.pb(i);
                            t=i;
                            goto end;
                        }
                    }
                    end:;
                    if(out[out.size()-1]==a)break;
                }
                for(int i=out.size()-1;i>=0;i--)cout<<m[out[i]]<<(i?" ":"\n");
            }
        }
    }
}