Hiring process8 levels
  1. 1 IQ Test
  2. 2 Additional Online Test (If Required)
  3. 3 Office Interview with Hiring Manager
  4. 4 Unpaid Test Task (Motivation Check)
  5. 5 Paid Test Task and Follow-Up Interview
  6. 6 Iterative Paid Test Tasks
  7. 7 Office Verification
  8. 8 Final Interview with the Founder

Problems > Happy Number

Happy Number

Difficulty: 1200 2000 ms 128 MB

math implementation

Repeatedly replace N by the sum of the squares of its digits. If the process reaches 1, N is happy; if it enters a cycle, it is not. Decide for N.

Input: one integer N.

Output: YES if N is happy, else NO.

Constraints:

  • 1 ≤ N ≤ 1018

Sample Tests

Input 1
19
Output 1
YES
Input 2
4
Output 2
NO

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