All problems

Hand of Straights

Medium · greedy

You are given a pile of cards. Each card shows a whole number, and cards[i] is the number on card i. Different cards may show the same number.

Deal out the whole pile into groups of exactly group_size cards, so that every card is in exactly one group and the numbers in each group are consecutive: they go up by one each time, like 4, 5, 6.

Return true if the pile can be dealt out this way, and false otherwise.

Examples

Example 1

Input: cards = [3, 4, 2, 6, 5, 3, 4, 5, 4], group_size = 3

Output: true

Deal 2, 3, 4 and 3, 4, 5 and 4, 5, 6.

Example 2

Input: cards = [1, 2, 3, 5], group_size = 2

Output: false

The 5 would need a 4 or a 6 beside it in its group, and there is neither, so the cards cannot be dealt out.

Example 3

Input: cards = [7, 7, 7], group_size = 1

Output: true

Every group is a single card, and a single card is always consecutive.

Constraints

• 1 <= len(cards) <= 10^4
• 0 <= cards[i] <= 10^9
• 1 <= group_size <= len(cards)