The "seq" list won't have repeating numbers, and will never have a length longer than 9. I am trying to get my code to return the missing integer in a given list from 0-9. I resolved to do this by removing a number from an integer "checklist" every time the system finds a matching number. Somehow, the IF statement in line 7 manages to get called when it's technically false.
def get_missing_element(seq):
missing = None
i = 0
f = 0
checklist = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
while f < len(checklist):
if checklist[f] == seq[i]:
checklist.remove(checklist[f])
print("i see", seq[i])
print("removed", checklist[f])
i = i + 1
f = 0
f = f + 1
return missing
seq = [1, 8, 2, 3, 4, 5, 0, 7, 9]
print(get_missing_element(seq))
I tried using For loops in the beginning, but I didn't know how to get a For loop to repeat itself without using a while loop. Does the root of my problem lie within the fact that I'm using a while loop here?
For a more general solution that doesn't rely on the elements being integers:
def get_missing_element(it):
# {} without : makes a set
checkset = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
for e in it:
# This will throw if `e` is repeated or not in `checkset`.
# Use `.discard(e)` to silently ignore such elements.
checkset.remove(e)
# tuple-unpacking will throw if there isn't exactly one element left.
r, = checkset
return r
seq = [1, 8, 2, 3, 4, 5, 0, 7, 9]
print(get_missing_element(seq))
Generally for questions of the form "is this a member", you want to use set, dict, or related (frozenset, collections.Counter, ...)