Question

I’m trying to write a function pairSum(data, value), in which if a list “data” contains two distict numbers whose sum equals “value,” the function returns true. I accomplished this using a list but is there a more efficient way I could write this function using dictionaries?

Answer 1

You could try using a set.

def pairSum(data, value):
  s = set()
  for i in data:
    if (value - i) in s:
      return True
    else:
      s.add(i)
  else:
    return False