846. Hand of Straights

Using simple search

class Solution:
    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:
        # Check if divisible
        if len(hand) % groupSize != 0:
            return False

        hand.sort()        

        # No. of groups
        n = len(hand) // groupSize

        def findAndRemove(num, c):
            if c == groupSize:
                return True

            for e in hand:
                if e - 1 == num:
                    hand.remove(e)
                    return findAndRemove(e, c + 1)
                    break

            return False

        for i in range(n):
            first = hand.pop(0)
            if not findAndRemove(first, 1):
                return False

        return True

Using dictionary

class Solution:
    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:
        # Check if divisible
        if len(hand) % groupSize != 0:
            return False

        # Sort for order
        hand.sort()        

        # No. of groups
        n = len(hand) // groupSize

        # Get counts
        d = defaultdict(int)
        for e in hand:
            d[e] += 1

        def findAndRemove(num, c):
            if c == groupSize:
                return True

            count = d[num + 1]
            if count > 0:
                d[num + 1] -= 1
                return findAndRemove(num + 1, c + 1)

            return False

        def findFirst():
            for k, v in d.items():
                if v > 0:
                    return k

        for i in range(n):
            first = findFirst()
            d[first] -= 1
            if not findAndRemove(first, 1):
                return False

        return True