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 <algorithm>
#include <queue>
#include <cstring>
#include <cmath>
#include <cstdio>

#define INF 1 << 28

using namespace std;

typedef double Weight; 

struct Edge{
    int src;
    int dst;
    Weight weight;

    Edge(int src, int dst, Weight weight):
        src(src), dst(dst), weight(weight){ }
};

struct Node{
    int index;
    int cost;
    int prev;

    Node(int index, int cost, int prev) :
        index(index), cost(cost), prev(prev){ }
};

bool operator <(const Node &a, const Node &b){
    if(a.cost == b.cost){
        return a.index > b.index;
    }else{
        return a.cost > b.cost;
    }
}

void dijkstra(int s, vector<int> &costs, vector<int> &prev, vector<vector<Edge> > &edges){
    int n=costs.size();
    bool picked[n];
    priority_queue<Node> q;

    costs.assign(n,INF);
    prev.assign(n,-1);
    costs[s] = 0;
    memset(picked, false, sizeof(picked));
    q.push(Node(0,0,-2));

    while(!q.empty()){
        Node fix = q.top(); 
        q.pop();
        if(prev[fix.index] != -1) continue;
       
        picked[fix.index] = true;
        costs[fix.index] = fix.cost;

        prev[fix.index] = fix.prev;

        for(int i=0;i<edges[fix.index].size();i++){ //foreach edge from fixed
            if(costs[edges[fix.index][i].dst] > costs[fix.index] + edges[fix.index][i].weight){
                q.push(Node(edges[fix.index][i].dst, edges[fix.index][i].weight + costs[fix.index], fix.index));
            }
        }
    }
}

vector<int> createpath(vector<int> &prev, int e){
    vector<int> ret;
    int pos = e;
    while(1){
        ret.push_back(pos);
        pos = prev[pos];
        if(pos == -2){
            reverse(ret.begin(),ret.end());
            return ret;
        }
    }
}

struct building{
    int index;
    int x;
    int y;
    
    building(int index, int x, int y):
        index(index), x(x), y(y){}
};

int main(){
    int n;
    while(cin >> n && n){
        vector<vector<Edge> > edges(n);
        vector<int> cost(n);
        vector<int> prev(n);
        vector<building> b;
        vector<int> ans;
        double dist;
        int m;
        int src,dst;
        int index,x,y;

        for(int i=0;i<n;i++){
            cin >> index >> x >> y;
            b.push_back(building(index-1,x,y));
        }

        for(int i=0;i<n;i++){
            for(int j=i+1;j<n;j++){
                dist = sqrt(pow(b[i].x - b[j].x,2) + pow(b[i].y - b[j].y, 2));
                if(dist <= 50){
                    edges[i].push_back(Edge(i,j,dist));
                    edges[j].push_back(Edge(j,i,dist));
                }
            }
        }
        
        cin >> m;
        for(int i=0;i<m;i++){
            cin >> src >> dst;
            dijkstra(src-1, cost, prev, edges);
            if(cost[dst-1] == INF){
                cout << "NA" << endl;
            }else{
                ans = createpath(prev,dst-1);
                for(int j=0;j<ans.size()-1;j++){
                    cout << ans[j]+1 << " ";
                }
                cout << ans.back()+1 << endl;
            }
        }
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <climits>
#include <queue>
#include <cmath>
using namespace std;

typedef pair<double,int> P;

const double INF = 1000000000;
struct edge { int to; double cost; };
vector<edge> G[1001];

void solve(int s, int g) {
    double d[1001]; fill(d, d+1001, INF);
    int prv[1001]; fill(prv, prv+1001, -1);
    priority_queue<P, vector<P>, greater<P> > q;
    d[s] = 0;
    q.push(make_pair(0, s));
    while ( ! q.empty()) {
        int v = q.top().second;
        q.pop();
        for (int i=0; i<(int)G[v].size(); ++i) {
            edge &e = G[v][i];
            if (e.cost != INF && d[v] + e.cost < d[e.to]) {
                d[e.to] = d[v] + e.cost;
                q.push(make_pair(d[e.to], e.to));
                prv[e.to] = v;
            }
        }
    }
    int k = g;
    if (prv[k] < 0) {
        cout << "NA" << endl;
    } else {
        vector<int> ret;
        while (0 <= k) {
            ret.push_back(k);
            k = prv[k];
        }
        for (int i=ret.size()-1; i>=0; --i) {
            cout << ret[i] << (i != 0 ? " " : "");
        }
        cout << endl;
    }
}

int main() {
    int n, m, s, g;
    int b[1000], x[1000], y[1000];
    while (cin >> n, n) {
        for (int i=0; i<n; ++i) {
            cin >> b[i] >> x[i] >> y[i];
        }
        for (int i=0; i<1001; ++i) {
            G[i].clear();
        }
        for (int i=0; i<n; ++i) {
            for (int j=i+1; j<n; ++j) {
                int cost = (x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]);
                if (2500 < cost) {
                    G[b[i]].push_back((edge){b[j], INF});
                    G[b[j]].push_back((edge){b[i], INF});
                } else {
                    G[b[i]].push_back((edge){b[j], sqrt(cost)});
                    G[b[j]].push_back((edge){b[i], sqrt(cost)});
                }
            }
        }
        cin >> m;
        for (int i=0; i<m; ++i) {
            cin >> s >> g;
            solve(s, g);
        }
    }
    return 0;
}