Delete unless code

zerosumset/zerosumset.py

-"""
-From Wikipedia:
-
-In computer science, the subset sum problem is an important decision problem in complexity theory and cryptography. There are several equivalent formulations of the problem. One of them is: given a set (or multiset) of integers, is there a non-empty subset whose sum is zero? For example, given the set ~{−7, −3, −2, 9000, 5, 8}~, the answer is yes because the subset ~{−3, −2, 5}~ sums to zero. 
-
-[Wikipedia: Subset sum problem](https://en.wikipedia.org/wiki/Subset_sum_problem)
-"""
-
-from z3 import *
-
-elems = [-7, -3, -2, 9000, 5, 8]
-
-n = len(elems)
-
-# Symbolic variables: is_in[i] is 1, if element i is in the zero sum subset, 0 otherwise
-is_in = [Int(f"{i}") for i in range(n)]
-
-# Create Z3 solver
-s = Solver()
-
-# First constraint: is_in[i] is either 0 or 1
-for i in range(n):
-  s.add(Or(is_in[i] == 0, is_in[i] == 1))
-
-# Second constraint: at least one element should be in the zero sum subset:
-s.add(Sum(is_in) > 0)
-
-# Third constraint: the sum of the elements in the zero sum subset should be zero:
-s.add(Sum([elems[i] * is_in[i] for i in range(n)]) == 0)
-
-# Check satisfiability and print solution if found
-if s.check() == sat:
-  print([elems[i] for i in range(n) if s.model().eval(is_in[i], model_completion=True) == 1])
-else:
-  print("Unsatisfiable!")
-
-