From fabf1c9334a86d55be133da851cafccc9e6319fe Mon Sep 17 00:00:00 2001 From: William Carroll Date: Wed, 12 Feb 2020 16:58:29 +0000 Subject: Tidy up structure of briefcase I had a spare fifteen minutes and decided that I should tidy up my monorepo. The work of tidying up is not finished; this is a small step in the right direction. TL;DR - Created a tools directory - Created a scratch directory (see README.md for more information) - Added README.md to third_party - Renamed delete_dotfile_symlinks -> symlinkManager - Packaged symlinkManager as an executable symlink-mgr using buildGo --- scratch/data_structures_and_algorithms/norman.py | 78 ++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 scratch/data_structures_and_algorithms/norman.py (limited to 'scratch/data_structures_and_algorithms/norman.py') diff --git a/scratch/data_structures_and_algorithms/norman.py b/scratch/data_structures_and_algorithms/norman.py new file mode 100644 index 000000000000..379ba92abba8 --- /dev/null +++ b/scratch/data_structures_and_algorithms/norman.py @@ -0,0 +1,78 @@ + + + +# Write a function with the following type signature:L +# equal? :: String -> String -> Bool +# +# Determine equality between two inputs with backspace characters encoded as +# "<". + +################################################################################ +# Solution 1 +################################################################################ + +# from collections import deque + +# def equal(a, b): +# sa = deque() +# sb = deque() + +# for c in a: +# if c == '<': +# sa.pop() +# else: +# sa.append(c) + +# for c in b: +# if c == '<': +# sb.pop() +# else: +# sb.append(c) + +# return sa == sb + +################################################################################ +# Solution 2 +################################################################################ + +def handle_dels(num_dels, i, xs): + if i < 0: + return -1 + + while xs[i] == '<': + num_dels += 1 + i -= 1 + + while num_dels > 0 and xs[i] != '<': + num_dels -= 1 + i -= 1 + + if xs[i] == '<': + return handle_dels(num_dels, i, xs) + else: + return i + +def update_index(i, xs): + # TODO: Indexing into non-available parts of a string. + if xs[i] != '<' and xs[i - 1] != '<': + return i - 1 + + elif xs[i - 1] == '<': + return handle_dels(0, i - 1, xs) + +def equal(a, b): + ia = len(a) - 1 + ib = len(b) - 1 + + while ia >= 0 and ib >= 0: + if a[ia] != b[ib]: + return False + ia = update_index(ia, a) + ib = update_index(ib, b) + + if ia != 0: + return update_index(ia, a) <= -1 + if ib != 0: + return update_index(ib, b) <= -1 + + return True -- cgit 1.4.1