## Challenges

Reddit challenges in python language.

Files Code and Result

### challenge313_easy

```'''
Given a sorted list of distinct integers, write a function that returns whether
there are two integers in the list that add up to 0. For example, you would
return true if both -14435 and 14435 are in the list, because -14435 + 14435 = 0.
Also return true if 0 appears in the list.
Examples

[1, 2, 3] -> false
[-5, -3, -1, 2, 4, 6] -> false
[] -> false
[-1, 1] -> true
[-97364, -71561, -69336, 19675, 71561, 97863] -> true
[-53974, -39140, -36561, -23935, -15680, 0] -> true

Optional Bonus Challenge

Today's basic challenge is a simplified version of the subset sum problem.
The bonus is to solve the full subset sum problem. Given a sorted list of
distinct integers, write a function that returns whether there is any
non-empty subset of the integers in the list that adds up to 0.

Examples of subsets that add up to 0 include:

[0]
[-3, 1, 2]
[-98634, -86888, -48841, -40483, 2612, 9225, 17848, 71967, 84319, 88875]

So if any of these appeared within your input, you would return true.

If you decide to attempt this optional challenge, please be aware that the
subset sum problem is NP-complete. This means that's it's extremely unlikely
that you'll be able to write a solution that works efficiently for large inputs.
If it works for small inputs (20 items or so) that's certainly good enough.
Bonus Challenge Examples

The following inputs should return false:

[-83314, -82838, -80120, -63468, -62478, -59378, -56958, -50061, -34791,
-32264, -21928, -14988, 23767, 24417, 26403, 26511, 36399, 78055]
[-92953, -91613, -89733, -50673, -16067, -9172, 8852, 30883, 46690, 46968,
56772, 58703, 59150, 78476, 84413, 90106, 94777, 95148]
[-94624, -86776, -85833, -80822, -71902, -54562, -38638, -26483, -20207,
-1290, 12414, 12627, 19509, 30894, 32505, 46825, 50321, 69294]
[-83964, -81834, -78386, -70497, -69357, -61867, -49127, -47916, -38361,
-35772, -29803, -15343, 6918, 19662, 44614, 66049, 93789, 95405]
[-68808, -58968, -45958, -36013, -32810, -28726, -13488, 3986, 26342, 29245,
30686, 47966, 58352, 68610, 74533, 77939, 80520, 87195]

The following inputs should return true:

[-97162, -95761, -94672, -87254, -57207, -22163, -20207, -1753, 11646, 13652,
14572, 30580, 52502, 64282, 74896, 83730, 89889, 92200]
[-93976, -93807, -64604, -59939, -44394, -36454, -34635, -16483, 267, 3245,
8031, 10622, 44815, 46829, 61689, 65756, 69220, 70121]
[-92474, -61685, -55348, -42019, -35902, -7815, -5579, 4490, 14778, 19399,
34202, 46624, 55800, 57719, 60260, 71511, 75665, 82754]
[-85029, -84549, -82646, -80493, -73373, -57478, -56711, -42456, -38923,
-29277, -3685, -3164, 26863, 29890, 37187, 46607, 69300, 84808]
[-87565, -71009, -49312, -47554, -27197, 905, 2839, 8657, 14622, 32217, 3556
'''
def subset(l):
lst_sum = 0
l = re.findall('[-]\d+|\d+', l)
l = list(map(int, l))
for num in l:
num_pos = num * -1
if 0 or num_pos in l:
return True
return False

def zubset(l):
l = re.findall('[-]\d+|\d+', l)
l = list(map(int, l))
for x in range(2, len(l)):
test = list(itertools.combinations(l, x))
for tup in test:
num = sum(tup)
#print(num)
if num ==  0:
return True
return False

import itertools

lsts = '''[0]
[-3, 1, 2]
[-98634, -86888, -48841, -40483, 2612, 9225, 17848, 71967, 84319, 88875]'''

lists = '''[-83314, -82838, -80120, -63468, -62478, -59378, -56958, -50061, -34791, -32264, -21928, -14988, 23767, 24417, 26403, 26511, 36399, 78055]
[-92953, -91613, -89733, -50673, -16067, -9172, 8852, 30883, 46690, 46968, 56772, 58703, 59150, 78476, 84413, 90106, 94777, 95148]
[-94624, -86776, -85833, -80822, -71902, -54562, -38638, -26483, -20207, -1290, 12414, 12627, 19509, 30894, 32505, 46825, 50321, 69294]
[-83964, -81834, -78386, -70497, -69357, -61867, -49127, -47916, -38361, -35772, -29803, -15343, 6918, 19662, 44614, 66049, 93789, 95405]
[-68808, -58968, -45958, -36013, -32810, -28726, -13488, 3986, 26342, 29245, 30686, 47966, 58352, 68610, 74533, 77939, 80520, 87195]
[-97162, -95761, -94672, -87254, -57207, -22163, -20207, -1753, 11646, 13652, 14572, 30580, 52502, 64282, 74896, 83730, 89889, 92200]
[-93976, -93807, -64604, -59939, -44394, -36454, -34635, -16483, 267, 3245, 8031, 10622, 44815, 46829, 61689, 65756, 69220, 70121]
[-92474, -61685, -55348, -42019, -35902, -7815, -5579, 4490, 14778, 19399, 34202, 46624, 55800, 57719, 60260, 71511, 75665, 82754]
[-85029, -84549, -82646, -80493, -73373, -57478, -56711, -42456, -38923, -29277, -3685, -3164, 26863, 29890, 37187, 46607, 69300, 84808]
[-87565, -71009, -49312, -47554, -27197, 905, 2839, 8657, 14622, 32217, 35567, 38470, 46885, 59236, 64704, 82944, 86902, 90487]'''

import re

lsts = lsts.splitlines()

for lst in lsts:
truth = subset(lst)
print(truth)
print('-------------------------')
lists = lists.splitlines()

for lst in lists:
truth = zubset(lst)
print(truth)
```

### Result

```True
False
False
-------------------------
False
False
False
False
False
True
True
True
True
True
```