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 <algorithm>
#include <map>
#include <string>
#include <vector>
#include <cmath>
using namespace std;

#define REP(i,n) for(int i = 0; i < (int)(n); ++i)
#define pb push_back
#define ALL(a) (a).begin(),(a).end()

const int INF = 100000000;
const int MAX_V = 1000;
const int MAX_E = 1000000;

int x[MAX_V], y[MAX_V];
double cost[MAX_V][MAX_V];
double d[MAX_V];
bool used[MAX_V];
int pre[MAX_V];
int V, E;

bool flag_end = false;

void init_cost() {
    REP(i, V) REP(j, V) cost[i][j] = INF;
}

void input() {
    scanf("%d", &V);

    if (V == 0) {
        flag_end = true;
        return;
    }

    init_cost();

    REP(i, V) {
        scanf("%*d%d%d", &x[i], &y[i]);
    }

    REP(i, V) {
        REP(j, V) {
            cost[i][j] = hypot(1.0*x[i] - x[j], 1.0*y[i] - y[j]);
        }
    }
}

//s: start
void dijkstra(int s) {
    REP(i, V) d[i] = INF;
    REP(i, V) used[i] = false;
    REP(i, V) pre[i] = -1;
    d[s] = 0;

    while (true) {
        int v = -1;
        REP(u, V) if (!used[u] && (v == -1 | d[u] < d[v])) v = u;

        if (v == -1) break;
        used[v] = true;

        REP(u, V) {
            if (cost[v][u] <= 50 && d[u] > d[v] + cost[v][u]) {
                d[u] = d[v] + cost[v][u];
                pre[u] = v;
            }
        }
    }
}

//t: terminal
vector<int> get_path(int t) {
    vector<int> path;
    for (; t != -1; t = pre[t]) path.pb(t);
    reverse(ALL(path));
    return path;
}

void solve() {
    int m;
    scanf("%d", &m);

    REP(i, m) {
        int s, g;
        scanf("%d%d", &s, &g);
        s--; g--;
        dijkstra(s);
        if (d[g] != INF) {
            vector<int> path = get_path(g);
            REP(i, path.size()) printf("%d ", path[i] + 1);
        } else {
            printf("NA");
        }
        printf("\n");
    }
}

int main() {
    while (true) {
        input();
        if (flag_end) return 0;
        solve();
    }
    return 0;
}

C++: #include<iostream>
#include<queue>
#include<vector>
#include<cstring>
#include<functional>
using namespace std;
typedef pair<double, int> P;
priority_queue<P, vector<P>, greater<P>> Q;
#define MAX_N 1005
int x[MAX_N], y[MAX_N]; double dist[MAX_N];
vector<int>path[MAX_N]; vector<P>X[MAX_N];
void dijkstra(int a, int b) {
	memset(dist, 1e+9, sizeof(dist));
	for (int i = ; i < MAX_N; i++) { path[i].clear(); }
	Q.push(make_pair(0.0, a)); dist[a] = 0; path[a].push_back(a);
	while (!Q.empty()) {
		pair<double, int>pa = Q.top(); Q.pop();
		double a1 = pa.first; int a2 = pa.second;
		for (int i = 0; i < X[a2].size(); i++) {
			int to = X[a2][i].second; double dis = X[a2][i].first;
			if (dist[to] > a1 + dis) {
				dist[to] = a1 + dis; path[to].clear();
				path[to] = path[a2]; path[to].push_back(to);
				Q.push(make_pair(dist[to], to));
			}
		}
	}
	if (path[b].size() == 0) { cout << "NA" << endl; }
	else {
		for (int i = 0; i < path[b].size(); i++) { if (i) { cout << ' '; } cout << path[b][i]; }
		cout << endl;
	}
}
int main() {
	int N, Q, s, g;
	while (true) {
		cin >> N; if (N == 0) { break; }
		for (int i = 0; i < N; i++) { cin >> x[i] >> y[i]; }
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				double dist2 = (x[i] - x[j])*(x[i] - x[j]) + (y[i] - y[j])*(y[i] - y[j]);
				if (dist2 <= 50.0) {
					X[i].push_back(make_pair(dist2, j));
				}
			}
		}
		cin >> Q; for (int i = 0; i < Q; i++) { cin >> s >> g; dijkstra(s, g); }
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>

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

std::vector<int> dijkstra(int, int);
double len[1001][1001];
const double INF = 10000000;

int main(){
	int n;
	while(std::cin >> n, n){
		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;
			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");
				}
			}
		}
	}
}

std::vector<int> dijkstra(int s, int e){
	double dist[1001]; int used[1001]; int prev[1001];
	std::fill(dist, dist+1001, INF);
	std::fill(used, used+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;
	}
}