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<cmath>
#include<queue>
using pii = std::pair<double, int>;

typedef struct edge{
  int from, to;
  double dist;
}edge;

typedef struct obj{
  int x, y;
}obj;

double dist(obj a, obj b){
  double i = (a.x - b.x), j = (a.y - b.y);
  return std::sqrt(i*i + j*j);
}

void solve(int s, int t, std::vector<std::vector<edge> > &G){
  int n = G.size();
  std::vector<int> ans(n, -1);  std::vector<double> d(n, 1e9);
  std::priority_queue<pii, std::vector<pii>, std::greater<pii>> que;
  que.push(pii(0, s));
  d[s] = 0;
  while(not que.empty()){
    int v = que.top().second;
    double c = que.top().first;
    que.pop();
    for (int i = 0; i < G[v].size(); i++) {
      int u = G[v][i].to;
      if(d[u] > c + G[v][i].dist){
        d[u] = c + G[v][i].dist;
        que.push(pii(d[u], u));
        ans[u] = v;
      }
    }
  }
  if(ans[t] == -1){
    std::cout << "NA" << std::endl;
    return;
  }
  std::vector<int> real_ans;
  real_ans.push_back(t);
  while(ans[t] != -1) {
    real_ans.push_back(ans[t]);
    t = ans[t];
  }
  for (int i = 0; i < real_ans.size(); i++) {
    std::cout << real_ans[real_ans.size() - i - 1] + 1;
    if(i == real_ans.size() - 1)std::cout << std::endl;
    else std::cout << " ";
  }
}
           

int main(){
  int n, m;
  while(std::cin >> n){
    if(n == 0) break;
    std::vector<std::vector<edge> > G(n);
    std::vector<obj> p(n);
    for (int i = 0; i < n; i++) {
      int b, x, y;
      std::cin >> b >> x >> y;
      p[--b] = obj{x, y};
    }
    for (int i = 0; i < n; i++) {
      for (int j = i + 1; j < n; j++) {
        // std::cout << "i:" << i << " j:" << j << " " << dist(p[i], p[j]) << std::endl;
        if(dist(p[i], p[j]) <= 50.){
          // std::cout << "hoge" << std::endl;
          G[i].push_back(edge{i, j, dist(p[i], p[j])});
          G[j].push_back(edge{j, i, dist(p[i], p[j])});
        }
      }
    }
    std::cin >> m;
    for (int i = 0; i < m; i++) {
      int s, t;
      std::cin >> s >> t;
      solve(--s, --t, G);
      // std::cout << "s:" << s << " t:" << t << std::endl;
    }
  }
  return 0;
}

C++: #include <stdio.h>
#include <cmath>
#include <algorithm>
#include <stack>
#include<iostream>
using namespace std;

struct Point{
	double x,y;
};

int main(){

	int n,m,checkTable[101],path[101],id,start,goal,count,min_index;
	double distance[101][101],x,y,calc[101][101],min_value;
	bool canGO[101];
	Point table[101];
	stack<int> S;

	while(true){
		scanf("%d",&n);
		if(n == 0)break;

		for(int i=1; i <= n; i++){
			scanf("%d %lf %lf",&id,&x,&y);
			table[id].x = x;
			table[id].y = y;
		}

		for(int i = 1; i <= n; i++){
			for(int k = 1; k <= n; k++){
				distance[i][k] = sqrt((table[i].x-table[k].x)*(table[i].x-table[k].x)+(table[i].y-table[k].y)*(table[i].y-table[k].y));
			}
		}

		scanf("%d",&m);

		for(int i = 1; i <= m; i++){
			scanf("%d %d",&start,&goal);

			for(int k = 1; k <= n; k++){
				checkTable[k] = 0;
				if(distance[start][k] < 50 || fabs(distance[start][k] - 50) < 0.00000001){
					canGO[k] = true;
				}else{
					canGO[k] = false;
				}
				path[k] = start;
				for(int p = 1; p <= n; p++)calc[k][p] = distance[k][p];
			}

			count = 1;
			checkTable[start] = 1;

			while(count < n){
				min_value = 1000000000;

				for(int k = 1; k <= n; k++){
					if(checkTable[k] == 0 && canGO[k] == true && calc[start][k] < min_value){
						min_value = calc[start][k];
						min_index = k;
					}
				}

				if(min_value == 1000000000)break;

				checkTable[min_index] = 1;
				count++;

				for(int p = 1; p <= n; p++){
					if((canGO[p] == false || calc[start][p] > calc[start][min_index]+calc[min_index][p]) && (distance[min_index][p] < 50 || fabs(distance[min_index][p] - 50) < 0.00000001)){
						calc[start][p] = calc[start][min_index]+calc[min_index][p];
						canGO[p] = true;
						path[p] = min_index;
					}
				}
			}

			if(canGO[goal] == false)cout<<"NA"<<endl;
			else{
				int t = goal;
				while(true){
					S.push(t);
					t = path[t];
					if(t == start)break;
				}
				printf("%d",start);
				while(!S.empty()){
                    cout<<" "<<S.top();
					S.pop();
				}
				cout<<endl;
			}
		}
	}


	return 0;
}