LeetCode in Kotlin
2799. Count Complete Subarrays in an Array
Medium
You are given an array nums consisting of positive integers.
We call a subarray of an array complete if the following condition is satisfied:
- The number of distinct elements in the subarray is equal to the number of distinct elements in the whole array.
Return the number of complete subarrays.
A subarray is a contiguous non-empty part of an array.
Example 1:
Input: nums = [1,3,1,2,2]
Output: 4
Explanation: The complete subarrays are the following: [1,3,1,2], [1,3,1,2,2], [3,1,2] and [3,1,2,2].
Example 2:
Input: nums = [5,5,5,5]
Output: 10
Explanation: The array consists only of the integer 5, so any subarray is complete. The number of subarrays that we can choose is 10.
Constraints:
1 <= nums.length <= 10001 <= nums[i] <= 2000
Solution
class Solution {
fun countCompleteSubarrays(nums: IntArray): Int {
val n = nums.size
var map = IntArray(2001)
var distinct = 0
var last = 0
for (i in 0 until n) {
map[nums[i]]++
if (map[nums[i]] == 1) {
distinct++
last = i
}
}
map = IntArray(2001)
for (i in 0..last) map[nums[i]]++
var ans = 0
for (i in 0 until n) {
ans += n - last
map[nums[i]]--
if (map[nums[i]] == 0) {
var possLast = 0
var j = last + 1
while (j < n && map[nums[i]] == 0) {
map[nums[j]]++
possLast = j
++j
}
last = if (map[nums[i]] > 0) {
possLast
} else break
}
}
return ans
}
}