1296. Divide Array in Sets of K Consecutive Numbers #

题目 #

Given an array of integers nums and a positive integer k, check whether it is possible to divide this array into sets of k consecutive numbers.

Return true if it is possible. Otherwise, return false.

Example 1:

Input: nums = [1,2,3,3,4,4,5,6], k = 4
Output: true
Explanation: Array can be divided into [1,2,3,4] and [3,4,5,6].

Example 2:

Input: nums = [3,2,1,2,3,4,3,4,5,9,10,11], k = 3
Output: true
Explanation: Array can be divided into [1,2,3] , [2,3,4] , [3,4,5] and [9,10,11].

Example 3:

Input: nums = [1,2,3,4], k = 3
Output: false
Explanation: Each array should be divided in subarrays of size 3.

Constraints:

• 1 <= k <= nums.length <= 100000
• 1 <= nums[i] <= 1000000000

题目大意 #

给你一个整数数组 nums 和一个正整数 k，请你判断是否可以把这个数组划分成一些由 k 个连续数字组成的集合。 如果可以，请返回 true；否则，返回 false。

解题思路 #

贪心算法

• 对nums升序排序
• 对nums内数字进行哈希计数（key:数字，value:数量）
• 遍历nums中的数字，以数量大于1的数字作为连续数字开头，寻找连续数字后续元素，若无法找到 k 个连续数字则返回false
• 所有数字都能找到 k 个连续数字返回true

##代码

package leetcode

import "sort"

func isPossibleDivide(nums []int, k int) bool {
	mp := make(map[int]int)
	for _, v := range nums {
		mp[v] += 1
	}
	sort.Ints(nums)
	for _, num := range nums {
		if mp[num] == 0 {
			continue
		}
		for diff := 0; diff < k; diff++ {
			if mp[num+diff] == 0 {
				return false
			}
			mp[num+diff] -= 1
		}
	}
	return true
}