LeetCode in Kotlin
2447. Number of Subarrays With GCD Equal to K
Medium
Given an integer array nums and an integer k, return the number of subarrays of nums where the greatest common divisor of the subarray’s elements is k.
A subarray is a contiguous non-empty sequence of elements within an array.
The greatest common divisor of an array is the largest integer that evenly divides all the array elements.
Example 1:
Input: nums = [9,3,1,2,6,3], k = 3
Output: 4
Explanation: The subarrays of nums where 3 is the greatest common divisor of all the subarray’s elements are:
-
[9,3,1,2,6,3]
-
[9,3,1,2,6,3]
-
[9,3,1,2,6,3]
-
[9,3,1,2,6,3]
Example 2:
Input: nums = [4], k = 7
Output: 0
Explanation: There are no subarrays of nums where 7 is the greatest common divisor of all the subarray’s elements.
Constraints:
1 <= nums.length <= 10001 <= nums[i], k <= 109
Solution
class Solution {
private fun sol(a: Int, b: Int): Int {
return if (b == 0) {
a
} else {
sol(b, a % b)
}
}
fun subarrayGCD(nums: IntArray, k: Int): Int {
val n = nums.size
var cnt = 0
for (i in 0 until n) {
var gcd = 0
for (j in i until n) {
gcd = sol(gcd, nums[j])
if (gcd == k) {
cnt++
}
if (gcd < k) {
break
}
}
}
return cnt
}
}