tvl-depot/data_structures_and_algorithms/merge-sort.py
William Carroll 5c9079a410 Splice ./universe directory into ./
Manually merging:
- README.md: I added the description from universe/README.md into the heading of
  dotfiles/README.md.
- .envrc: dotfiles/.envrc was a superset of universe/.envrc
- .gitignore: Adding some of the ignored patterns from universe/.gitignore to
  dotfiles/.gitignore

Everything else here should be a simple rename.
2020-01-29 14:43:20 +00:00

28 lines
593 B
Python

# merge :: [a] -> [a] -> [a]
# merge([], []): []
# merge(xs, []): xs
# merge([], ys): ys
# merge(xs@[x|xs'], ys@[y|ys'])
# when y =< x: cons(y, merge(xs, ys'))
# when x < y: cons(x, merge(xs', ys))
def merge(xs, ys):
if xs == [] and ys == []:
return []
elif ys == []:
return xs
elif xs == []:
return ys
else:
x = xs[0]
y = ys[0]
if y <= x:
return [y] + merge(xs, ys[1:])
else:
return [x] + merge(xs[1:], ys)
print(merge([3, 4, 6, 10, 11, 15],
[1, 5, 8, 12, 14, 19]))