def test_n_sum(self):
self.assertEqual(n_sum(2, [-3, 5, 2, 3, 8, -9], 6), []) # noqa: E501
self.assertEqual(n_sum(3, [-5, -4, -3, -2, -1, 0, 1, 2, 3], 0),
sorted([[-5, 2, 3], [-2, 0, 2], [-4, 1,
3], [-3, 1, 2],
[-1, 0, 1], [-2, -1, 3], [-3, 0,
3]])) # noqa: E501
self.assertEqual(n_sum(3, [-1, 0, 1, 2, -1, -4], 0),
sorted([[-1, -1, 2], [-1, 0, 1]])) # noqa: E501
self.assertEqual(n_sum(4, [1, 0, -1, 0, -2, 2], 0),
sorted([[-2, -1, 1, 2], [-2, 0, 0, 2],
[-1, 0, 0, 1]])) # noqa: E501
self.assertEqual(
n_sum(4, [
7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 6, 4, -3, -2
], 10),
sorted([[-6, 2, 7, 7], [-6, 3, 6, 7], [-6, 4, 5, 7], [-6, 4, 6, 6],
[-5, 1, 7, 7], [-5, 2, 6, 7], [-5, 3, 5, 7], [-5, 3, 6, 6],
[-5, 4, 4, 7], [-5, 4, 5, 6], [-4, 0, 7, 7], [-4, 1, 6, 7],
[-4, 2, 5, 7], [-4, 2, 6, 6], [-4, 3, 4, 7], [-4, 3, 5, 6],
[-4, 4, 4, 6], [-3, -1, 7, 7], [-3, 0, 6,
7], [-3, 1, 5, 7],
[-3, 1, 6, 6], [-3, 2, 4, 7], [-3, 2, 5, 6], [-3, 3, 4, 6],
[-3, 4, 4, 5], [-2, -2, 7, 7], [-2, -1, 6,
7], [-2, 0, 5, 7],
[-2, 0, 6, 6], [-2, 1, 4, 7], [-2, 1, 5, 6], [-2, 2, 3, 7],
[-2, 2, 4, 6], [-2, 3, 4, 5], [-1, 0, 4, 7], [-1, 0, 5, 6],
[-1, 1, 3, 7], [-1, 1, 4, 6], [-1, 2, 3, 6], [-1, 2, 4, 5],
[-1, 3, 4, 4], [0, 1, 2, 7], [0, 1, 3, 6], [0, 1, 4, 5],
[0, 2, 3, 5], [0, 2, 4, 4], [1, 2, 3, 4]])) # noqa: E501
self.assertEqual(
n_sum(
2,
[[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]],
0, # noqa: E501
sum_closure=lambda a, b: a[0] + b[0]), # noqa: E501
[[[-3, 0], [3, 3]], [[-2, 1], [2, 2]]]) # noqa: E501
self.assertEqual(
n_sum(
2,
[[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]],
[0, 3], # noqa: E501
sum_closure=lambda a, b: [a[0] + b[0], a[1] + b[1]
], # noqa: E501
same_closure=lambda a, b: a[0] == b[0] and a[1] == b[1]
), # noqa: E501
[[[-3, 0], [3, 3]], [[-2, 1], [2, 2]]]) # noqa: E501
self.assertEqual(
n_sum(
2,
[[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]],
-5, # noqa: E501
sum_closure=lambda a, b: [a[0] + b[1], a[1] + b[0]
], # noqa: E501
compare_closure=lambda a, b: -1 if a[0] < b else 1
if a[0] > b else 0), # noqa: E501
[[[-9, 5], [8, 4]]]) # noqa: E501
def test_n_sum(self):
self.assertEqual(n_sum(2, [-3, 5, 2, 3, 8, -9], 6), []) # noqa: E501
self.assertEqual(n_sum(3, [-5, -4, -3, -2, -1, 0, 1, 2, 3], 0), sorted([[-5,2,3],[-2,0,2],[-4,1,3],[-3,1,2],[-1,0,1],[-2,-1,3],[-3,0,3]])) # noqa: E501
self.assertEqual(n_sum(3, [-1,0,1,2,-1,-4], 0), sorted([[-1,-1,2],[-1,0,1]])) # noqa: E501
self.assertEqual(n_sum(4, [1, 0, -1, 0, -2, 2], 0), sorted([[-2, -1, 1, 2], [-2, 0, 0, 2], [-1, 0, 0, 1]])) # noqa: E501
self.assertEqual(n_sum(4, [7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 6, 4, -3, -2], 10), sorted([[-6, 2, 7, 7], [-6, 3, 6, 7], [-6, 4, 5, 7], [-6, 4, 6, 6], [-5, 1, 7, 7], [-5, 2, 6, 7], [-5, 3, 5, 7], [-5, 3, 6, 6], [-5, 4, 4, 7], [-5, 4, 5, 6], [-4, 0, 7, 7], [-4, 1, 6, 7], [-4, 2, 5, 7], [-4, 2, 6, 6], [-4, 3, 4, 7], [-4, 3, 5, 6], [-4, 4, 4, 6], [-3, -1, 7, 7], [-3, 0, 6, 7], [-3, 1, 5, 7], [-3, 1, 6, 6], [-3, 2, 4, 7], [-3, 2, 5, 6], [-3, 3, 4, 6], [-3, 4, 4, 5], [-2, -2, 7, 7], [-2, -1, 6, 7], [-2, 0, 5, 7], [-2, 0, 6, 6], [-2, 1, 4, 7], [-2, 1, 5, 6], [-2, 2, 3, 7], [-2, 2, 4, 6], [-2, 3, 4, 5], [-1, 0, 4, 7], [-1, 0, 5, 6], [-1, 1, 3, 7], [-1, 1, 4, 6], [-1, 2, 3, 6], [-1, 2, 4, 5], [-1, 3, 4, 4], [0, 1, 2, 7], [0, 1, 3, 6], [0, 1, 4, 5], [0, 2, 3, 5], [0, 2, 4, 4], [1, 2, 3, 4]])) # noqa: E501
self.assertEqual(n_sum(2, [[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]], 0, # noqa: E501
sum_closure=lambda a, b: a[0] + b[0]), # noqa: E501
[[[-3, 0], [3, 3]], [[-2, 1], [2, 2]]]) # noqa: E501
self.assertEqual(n_sum(2, [[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]], [0, 3], # noqa: E501
sum_closure=lambda a, b: [a[0] + b[0], a[1] + b[1]], # noqa: E501
same_closure=lambda a, b: a[0] == b[0] and a[1] == b[1]), # noqa: E501
[[[-3, 0], [3, 3]], [[-2, 1], [2, 2]]]) # noqa: E501
self.assertEqual(n_sum(2, [[-3, 0], [-2, 1], [2, 2], [3, 3], [8, 4], [-9, 5]], -5, # noqa: E501
sum_closure=lambda a, b: [a[0] + b[1], a[1] + b[0]], # noqa: E501
compare_closure=lambda a, b: -1 if a[0] < b else 1 if a[0] > b else 0), # noqa: E501
[[[-9, 5], [8, 4]]]) # noqa: E501
def n_sum(n, nums, target):
if n == 2: # want answers with only 2 terms? easy!
results = two_sum(nums, target)
else:
results = []
prev_num = None
for index, num in enumerate(nums):
if prev_num is not None and \
same_closure(prev_num, num):
continue
prev_num = num
n_minus1_results = (
n_sum( # recursive call
n - 1, # a
nums[index + 1:], # b
target - num # c
) # x = n_sum( a, b, c )
) # n_minus1_results = x
n_minus1_results = (append_elem_to_each_list(
num, n_minus1_results))
results += n_minus1_results
return union(results)
def n_sum(n, nums, target, **kv):
"""
n: int
nums: list[object]
target: object
sum_closure: function, optional
Given two elements of nums, return sum of both.
compare_closure: function, optional
Given one object of nums and target, return -1, 1, or 0.
same_closure: function, optional
Given two object of nums, return bool.
return: list[list[object]]
Note:
1. type of sum_closure's return should be same
as type of compare_closure's first param
"""
def sum_closure_default(a, b):
return a + b
def compare_closure_default(num, target):
""" above, below, or right on? """
if num < target:
return -1
elif num > target:
return 1
else:
return 0
def same_closure_default(a, b):
return a == b
def n_sum(n, nums, target):
if n == 2: # want answers with only 2 terms? easy!
results = two_sum(nums, target)
else:
results = []
prev_num = None
for index, num in enumerate(nums):
if prev_num is not None and \
same_closure(prev_num, num):
continue
prev_num = num
n_minus1_results = (
n_sum( # recursive call
n - 1, # a
nums[index + 1:], # b
target - num # c
) # x = n_sum( a, b, c )
) # n_minus1_results = x
n_minus1_results = (append_elem_to_each_list(
num, n_minus1_results))
results += n_minus1_results
return union(results)
def two_sum(nums, target):
nums.sort()
lt = 0
rt = len(nums) - 1
results = []
while lt < rt:
sum_ = sum_closure(nums[lt], nums[rt])
flag = compare_closure(sum_, target)
if flag == -1:
lt += 1
elif flag == 1:
rt -= 1
else:
results.append(sorted([nums[lt], nums[rt]]))
lt += 1
rt -= 1
while (lt < len(nums)
and same_closure(nums[lt - 1], nums[lt])):
lt += 1
while (0 <= rt and same_closure(nums[rt], nums[rt + 1])):
rt -= 1
return results
def append_elem_to_each_list(elem, container):
results = []
for elems in container:
elems.append(elem)
results.append(sorted(elems))
return results
def union(duplicate_results):
results = []
if len(duplicate_results) != 0:
duplicate_results.sort()
results.append(duplicate_results[0])
for result in duplicate_results[1:]:
if results[-1] != result:
results.append(result)
return results
sum_closure = kv.get('sum_closure', sum_closure_default)
same_closure = kv.get('same_closure', same_closure_default)
compare_closure = kv.get('compare_closure', compare_closure_default)
nums.sort()
return n_sum(n, nums, target)
def compare(num, target):
if num[0] < target:
return -1
elif if num[0] > target:
return 1
else:
return 0
return [[-9, 5], [8, 4]]
(TL:DR) because -9 + 4 = -5
"""
from algorithms.arrays import n_sum
n = 4
a = [1, 0, -1, 0, -2, 2]
target = 0
print(n_sum(n, a, target))
def n_sum(n, nums, target, **kv):
"""
n: int
nums: list[object]
target: object
sum_closure: function, optional
Given two elements of nums, return sum of both.
compare_closure: function, optional
Given one object of nums and target, return -1, 1, or 0.
same_closure: function, optional
Given two object of nums, return bool.
return: list[list[object]]