Two Sets

Explanation

In this problem, we are provided a number n and we need to divide the array from 1 to n into two parts such that the sum of the elements in the first part is equal to the sum of the elements in the second part or print NO if it isn't possible.

We can do this by checking if the value (n * (n + 1)) / 2 is divisible by 2. If it is, then we output YES otherwise we will output NO.

If the sum is divisible by 2, then first we will find the first part of the array. We will intialize the variable sum with the value (n * (n + 1)) / 4. Then we will check if sum is greater than n. If it is, then we will subtract n from sum and add n to the first part of the array, also we will reduce n by 1.

Code

n = int(input())
s = (n * (n + 1)) // 2

if s % 2 == 0:
    print("YES")
    s //= 2

    arr1 = set()
    while s >= n:
        arr1.add(n)
        s -= n
        n -= 1

    if s > 0:
        arr1.add(s)

    print(len(arr1))
    print(*arr1)

    arr2 = set(range(1, n + 1)) - arr1
    print(len(arr2))
    print(*arr2)
else:
    print("NO")