Find maximum possible time HH:MM by permuting four given digits

Question

I recently took a coding test for a promotion at work. This was one of the tasks I really struggled with and was wondering what is the best way to do this. I used a load of

Answer 1

from itertools  import permutations
class Solution(object):
    def largestTimeFromDigits(self, A):
        arr = []
        for i in permutations(A,4):
            if int(str(i[0])+str(i[1])) < 24 and int(str(i[2])+ str(i[3])) < 60:
                arr.append(list(i))
        
        if arr:
            cnt = arr[0]
            for t in arr[1:]:
                if int(str(t[0])+str(t[1])) > int(str(cnt[0])+ str(cnt[1])):
                    cnt = t
                elif int(str(t[0])+str(t[1])) == int(str(cnt[0])+ str(cnt[1])):
                    if int(str(t[2])+str(t[3])) > int(str(cnt[2])+ str(cnt[3])):
                        cnt = t
            return str(cnt[0])+ str(cnt[1]) + ":" + str(cnt[2])+ str(cnt[3])  
        else:
            return ""