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 <sstream>
#include <map>
#include <queue>
#include <cmath>
using namespace std;

typedef pair <double, int> PDI;
typedef pair <PDI, vector <int> > PPV;
typedef priority_queue <PPV, vector <PPV>, greater <PPV> > QUEUE;

const double eps = 1e-9;
const int size = 1001;
int n, m;
int b[size], x[size], y[size];
map <int, int> cor;
bool path[size][size];
bool able[size][size];
double cost[size][size];
double min_cost[size][size];
int con[size][size];
int concnt[size];

string solve( int s_, int g_ )
{
    int start = cor[s_], goal = cor[g_];
    if ( !able[start][goal] ) return "NA";

    ostringstream os;
    QUEUE Q;
    PPV start_node( PDI( 0.0, start ), vector<int>() );
    Q.push( start_node );

    while ( !Q.empty() ) {
        PPV node = Q.top();
        Q.pop();
        double c = node.first.first;
        int ind = node.first.second;
        int number = b[ind];
        vector <int> route = node.second;
        route.push_back( number );

        if ( number == g_ ) {
            for ( vector <int> ::iterator it = route.begin(); it != route.end(); it++ ) {
                os << *it;
                if ( it + 1 != route.end() ) os << " ";
            }
            break;
        }

        for ( int i = 0; i < concnt[ind]; i++ ) {
            int next_ind = con[ind][i];
            double next_c = c + cost[ind][next_ind];
            if ( min_cost[ind][next_ind] < 0.0 || next_c < min_cost[ind][next_ind] ) {
                min_cost[ind][next_ind] = next_c;
                PPV next_node( PDI( next_c, next_ind ), route );
                Q.push( next_node );
            }
        }

    }

    return os.str();
}

// <
bool big_equal( double a, double b )
{
    if ( a < b ) return true;
    return fabs( a - b ) < eps;
}

double getDistance( int x1, int y1, int x2, int y2 )
{
    double x = ( x2 - x1 ), y = ( y2 - y1 );
    return sqrt( x * x + y * y );
}

int main( void )
{
    while ( cin >> n && n ) {
        // init
        for ( int i = 0; i < n; i++ ) {
            for ( int j = 0; j < n; j++ ) {
                path[i][j] = false;
                able[i][j] = false;
                min_cost[i][j] = -1.0;
            }
            concnt[i] = 0;
        }

        // input
        for ( int i = 0; i < n; i++ ) {
            cin >> b[i] >> x[i] >> y[i];
            cor[b[i]] = i;
        }

        for ( int i = 0; i < n; i++ ) {
            for ( int j = i+1; j < n; j++ ) {
                cost[i][j] = cost[j][i] = getDistance( x[i], y[i], x[j], y[j] );
            }
        }

        // proc
        for ( int i = 0; i < n; i++ ) {
            for ( int j = i+1; j < n; j++ ) {
                if ( big_equal( cost[i][j], 50.0 ) ) {
                    path[i][j] = path[j][i] = able[i][j] = able[j][i] = true;
                    con[i][concnt[i]] = j;
                    concnt[i]++;
                    con[j][concnt[j]] = i;
                    concnt[j]++;
                }
            }
        }

        for ( int k = 0; k < n; k++ ) {
            for ( int i = 0; i < n; i++ ) {
                for ( int j = 0; j < n; j++ ) {
                    if ( i == k || k == j || j == i ) continue;
                    if ( !able[i][k] || !able[k][j] ) continue;
                    able[i][j] = true;
                }
            }
        }

        // query
        cin >> m;
        for ( int i = 0; i < m; i++ ) {
            int s, t;
            cin >> s >> t;
            cout << solve( s, t ) << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<cstring>
#include<set>
#include<cmath>

double adjacive[1000][1000];
int field[1000][1000];
int prev[1000];
std::set<int> building;

int input();
void dijkstra(int start);
void output(int start,int goal);

int main()
{
	while(1)
	{
		int n;
		n=input();
		if(n==0)break;
		
		int m;
		std::cin>>m;
		for(int i=0;i<m;i++)
		{
			int bs,bg;
			std::cin>>bs>>bg;
			dijkstra(bs);
			output(bs,bg);
		}
	}
	return 0;
}

int input()
{
	int n;
	std::cin>>n;
	if(n==0)return 0;
	memset(field,0,sizeof(field));
	building.clear();

	for(int i=0;i<1000;i++){for(int j=0;j<1000;j++){adjacive[i][j]=1.0e+10;}}

	for(int i=0;i<n;i++)
	{
		int b,x,y;
		std::cin>>b>>x>>y;
		field[y][x]=b;
		building.insert(b);
	}
	for(int y=0;y<1000;y++)
	{
		for(int x=0;x<1000;x++)
		{
			if(field[y][x]!=0)
			{
				for(int i=-50;i<=50;i++)
				{
					for(int j=-50;j<=50;j++)
					{
						if(i+y>=0&&i+y<1000&&j+x>=0&&j+x<1000&&field[i+y][j+x]!=0&&i*i+j*j<=2500)
						{
							adjacive[field[y][x]-1][field[y+i][x+j]-1]=hypot(i,j);
						}
					}
				}
			}
		}
	}
	return n;
}

void dijkstra(int start)
{
	bool visited[1000];
	double cost[1000];
	memset(visited,0,sizeof(visited));
	memset(prev,-1,sizeof(prev));

	for(int i=0;i<1000;i++){cost[i]=1.0e+10;}
	
	cost[start-1]=0;
	while(1)
	{
		int u=-1;
		for(std::set<int>::iterator it=building.begin();it!=building.end();it++)
		{
			if(!visited[*it-1]&&(u==-1||cost[*it-1]<cost[u]))
			{
				u=*it-1;
			}
		}
		if(u==-1)break;
		visited[u]=true;
		for(std::set<int>::iterator it=building.begin();it!=building.end();it++)
		{
			if(cost[*it-1]>cost[u]+adjacive[u][*it-1])
			{
				cost[*it-1]=cost[u]+adjacive[u][*it-1];
				prev[*it-1]=u;
				
			}
		}
	}
}

void output(int start,int goal)
{
	int temp[1000];
	int b=goal-1;
	int i=0;
	bool isNA=true;

	while(prev[b]!=-1)
	{
		temp[i]=b+1;
		i++;
		b=prev[b];
		isNA=false;
	}

	if(start==goal)
	{
		std::cout<<start<<' '<<goal<<std::endl;
	}
	else if(isNA)
	{
		std::cout<<"NA"<<std::endl;
	}
	else
	{
		std::cout<<start;
		for(i=i-1;i>=0;i--)
		{
			std::cout<<' '<<temp[i];
		}
		std::cout<<std::endl;
	}
}