def no_subset_sum(c):
  n = len(c)
  if n == 0: return True #case: set length is 0
  if (c[0] > 0 or c[n-1] < 0): return True #case: all positive or all negative numbers in set, no zeroes

def subset_zero(a):
  #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
  if no_subset_sum(a): return False
  n, i = len(a), 0
  while (a[i] <= 0):
    if a[i] == 0: return True
    for t in range(n-1,i,-1):
      if (a[i] + a[t] == 0): return True
    i = i+1
  return False

#tests
t1 = [1,2,3]
t2 = [-5,-3,-1,2,4,6]
t3 = []
t4 = [-1,1]
t5 = [-97364, -71561, -69336, 19675, 71561, 97863]
t6 = [-53974, -39140, -36561, -23935, -15680, 0]