Two Equal Sets
Split 1..N into two sets with equal sums, or print NO. To keep the answer unique: build the first set GREEDILY from N downward (take a number whenever it still fits), and print it ascending. Output YES, then |set1|, set1, |set2|, set2 on separate lines.
Input: one integer N.
Output: NO, or the five lines described above.
Constraints:
- 1 ≤ N ≤ 105
Sample Tests
Input 1
7
Output 1
YES 3 1 6 7 4 2 3 4 5
Input 2
6
Output 2
NO
Discussion (opens after you solve — no spoilers before)
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