Problem: A sequence a_1,a_2,... ,a_n is said to be /\/\/\/ when the following conditions are satisfied:    * For each i = 1,2,..., n-2, a_i = a_{i+2}.   * Exactly two different numbers appear in the sequence.  You are given a sequence v_1,v_2,...,v_n whose length is even. We would like to make this sequence /\/\/\/ by replacing some of its elements. Find the minimum number of elements that needs to be replaced.

Submission attempts (in order):
from collections import Counter
from math import min

N = int(input())

arr = [input() for i in range(0,N)]

odd = arr[0::2]
even = arr[1::2]

odd_counter = Counter(odd)
even_counter = Counter(even)

odd_mode = odd_counter.most_common()[0][0]
even_mode = even_counter.most_common()[0][0]

odd_diff = (N / 2) - odd_counter.most_common()[0][1]
even_diff = (N / 2) - even_counter.most_common()[0][1]

if odd_mode != even_mode:
	print(odd_diff + even_diff)
else:
 	odd_diff2 = (N / 2) - odd_counter.most_common()[1][1]
	even_diff2 = (N / 2) - even_counter.most_common()[1][1]
    if odd_diff2 > even_diff2:
		print(odd_diff + even_diff2)
    else:
		print(odd_diff2 + even_diff)

from collections import Counter

N = int(input())

arr = [input() for i in range(0,N)]

odd = arr[0::2]
even = arr[1::2]

odd_counter = Counter(odd)
even_counter = Counter(even)

odd_mode = odd_counter.most_common()[0][0]
even_mode = even_counter.most_common()[0][0]

odd_diff = (N / 2) - odd_counter.most_common()[0][1]
even_diff = (N / 2) - even_counter.most_common()[0][1]

if odd_mode != even_mode:
	print(odd_diff + even_diff)
else:
 	odd_diff2 = (N / 2) - odd_counter.most_common()[1][1]
	even_diff2 = (N / 2) - even_counter.most_common()[1][1]
    if odd_diff2 > even_diff2:
		print(odd_diff + even_diff2)
    else:
		print(odd_diff2 + even_diff)


from collections import Counter

N = int(input())

arr = list(map(int, input().split(' ')))

print(arr)

odd = arr[0::2]
even = arr[1::2]

odd_counter = Counter(odd)
even_counter = Counter(even)

print(odd_counter.most_common())
print(even_counter.most_common())

odd_mode = odd_counter.most_common()[0][0]
even_mode = even_counter.most_common()[0][0]

odd_diff = (N / 2) - odd_counter.most_common()[0][1]
even_diff = (N / 2) - even_counter.most_common()[0][1]

if odd_mode != even_mode:
	print(int(odd_diff + even_diff))

elif odd_diff == N /2:
	print(N / 2)
else:
	odd_diff2 = (N / 2) - odd_counter.most_common()[1][1]
	even_diff2 = (N / 2) - even_counter.most_common()[1][1]
	if odd_diff2 > even_diff2:
		print(int(odd_diff + even_diff2))
	else:
		print(int(odd_diff2 + even_diff))


from collections import Counter

N = int(input())

arr = list(map(int, input().split(' ')))

odd = arr[0::2]
even = arr[1::2]

odd_counter = Counter(odd)
even_counter = Counter(even)

odd_mode = odd_counter.most_common()[0][0]
even_mode = even_counter.most_common()[0][0]

odd_diff = (N / 2) - odd_counter.most_common()[0][1]
even_diff = (N / 2) - even_counter.most_common()[0][1]

if odd_mode != even_mode:
	print(int(odd_diff + even_diff))
elif odd_diff == 0:
	print(int(N / 2))
else:
	odd_diff2 = (N / 2) - odd_counter.most_common()[1][1]
	even_diff2 = (N / 2) - even_counter.most_common()[1][1]
	if odd_diff2 > even_diff2:
		print(int(odd_diff + even_diff2))
	else:
		print(int(odd_diff2 + even_diff))


Verdicts: Runtime Error

Runtime Error

Runtime Error

Accepted