URAL 1209 1, 10, 100, 1000...

 1 import java.util.Arrays;
 2 import java.util.Scanner;
 3 
 4 public class P1209
 5 {
 6     public static void main(String args[])
 7     {
 8         long k[] = new long[100000];
 9         for (int i = 1; i < k.length; i++)
10             k[i] = (long) i * (i + 1) / 2;
11         try (Scanner cin = new Scanner(System.in))
12         {
13             while (cin.hasNext())
14             {
15                 int n = cin.nextInt();
16                 for (int i = 0; i < n; i++)
17                 {
18                     long x = cin.nextInt();
19                     if (x == 1)
20                         System.out.println(1);
21                     else if (Arrays.binarySearch(k, x - 1) >= 0)
22                         System.out.println(1);
23                     else
24                         System.out.println(0);
25                 }
26             }
27         }
28     }
29 }