List of Positive Integers - Python

Question

Given the list lst of positive integers, associate the largest duplicated element with the variable max_dup. If the list contains no duplicates, associate -1 with max_dup

Answer 1

You can use numpy unique function, something like this:

import numpy as np

def get_max_dup(mylist):

_, counts = np.unique(mylist, return_counts=True)

max_dup = max(counts)

if max_dup == 1:

return -1

else:

return max_dup

Answer 2

Super cool use of numpy in the first answer! Here is an older skool version that does the trick as well:

def get_max_dup(mylist):

# copy and call it myNums!

myNums = mylist.copy()

# remove pesky dups (set -> unique)

deduped = set(myNums)

# remove unique from myNums -> remove() nixes just the first

for num in deduped:

myNums.remove(num)

# nothing left (no dups); return -1

if len(myNums) == 0:

return -1

else:

return max(myNums)