#!/usr/bin/python3
"""Construct a fixed-size-node append-only skip list shape."""

if __name__ == '__main__':
    n = 100
    blockno = range(n)
    prev = [i-1 for i in blockno]
    jump = [((i ^ (i-1))) // 2 + 1 for i in blockno]
    skip = [i - j if j > 1 else -1 for i, j in zip(blockno, jump)]
    w = lambda n: '%3d' % n if n >= 0 else '   '
    print('blok', ''.join(w(i) for i in blockno))
    print('prev', ''.join(w(i) for i in prev))
    #print('jump', ''.join(w(i) for i in jump))
    print('skip', ''.join(w(i) for i in skip))