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merge_sorted_lists_task.py
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"""
my_list = [3, 4, 6, 10, 11, 15]
alices_list = [1, 5, 8, 12, 14, 19]
# Returns [1, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 19]
merge_lists(my_list, alices_list)
"""
def merge_sorted_lists_pop_method(list_1, list_2):
"""
pops off the lowest number between the two lists until both original lists are empty
time complexity: n^2/2 where n is the biggest list
space: complexity: n where n is the length of the biggest list
"""
new_list = []
cp_list_1 = list_1.copy()
cp_list_2 = list_2.copy()
while len(cp_list_1) > 0 or len(cp_list_2) > 0:
if len(cp_list_1) > 0 and len(cp_list_2) > 0:
# find lowest between 2
if cp_list_1[0] < cp_list_2[0]:
new_list.append(cp_list_1.pop(0))
else:
new_list.append(cp_list_2.pop(0))
# if there is only one list with values left...
elif len(cp_list_1) > 0:
new_list.append(cp_list_1.pop(0))
else:
new_list.append(cp_list_2.pop(0))
return new_list
assert merge_sorted_lists_pop_method([3, 4, 6, 10, 11, 15], [1, 5, 8, 12, 14, 19]) == [1, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 19]
# different length of lists
assert merge_sorted_lists_pop_method([3, 4, 6, 7, 10, 11, 15], [1, 5, 8, 12, 14, 19]) == [1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 14, 15, 19]
# empty list
assert merge_sorted_lists_pop_method([], [1, 5, 8, 12, 14, 19]) == [1, 5, 8, 12, 14, 19]
# 2 empty lists
assert merge_sorted_lists_pop_method([], []) == []
def merge_sorted_lists_pop_place_method(list_1, list_2):
"""
instead of popping which incurs n runtime every time, keep track of the place where we should pop and add that
value to the new sorted list
time complexity: n where n is the biggest list
space: complexity: n where n is the length of the biggest list
"""
new_list = []
list_1_pop_place = 0
list_2_pop_place = 0
while len(list_1) > list_1_pop_place or len(list_2) > list_2_pop_place:
if len(list_1) > list_1_pop_place and len(list_2) > list_2_pop_place:
# find lowest between 2
if list_1[list_1_pop_place] < list_2[list_2_pop_place]:
new_list.append(list_1[list_1_pop_place])
list_1_pop_place += 1
else:
new_list.append(list_2[list_2_pop_place])
list_2_pop_place += 1
# if there is only one list with values left...
elif len(list_1) > list_1_pop_place:
new_list.append(list_1[list_1_pop_place])
list_1_pop_place += 1
else:
new_list.append(list_2[list_2_pop_place])
list_2_pop_place += 1
return new_list
assert merge_sorted_lists_pop_place_method([3, 4, 6, 10, 11, 15], [1, 5, 8, 12, 14, 19]) == [1, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 19]
# different length of lists
assert merge_sorted_lists_pop_place_method([3, 4, 6, 7, 10, 11, 15], [1, 5, 8, 12, 14, 19]) == [1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 14, 15, 19]
# empty list
assert merge_sorted_lists_pop_place_method([], [1, 5, 8, 12, 14, 19]) == [1, 5, 8, 12, 14, 19]
# 2 empty lists
assert merge_sorted_lists_pop_place_method([], []) == []