LeetCode in Kotlin
413. Arithmetic Slices
Medium
An integer array is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.
- For example,
[1,3,5,7,9],[7,7,7,7], and[3,-1,-5,-9]are arithmetic sequences.
Given an integer array nums, return the number of arithmetic subarrays of nums.
A subarray is a contiguous subsequence of the array.
Example 1:
Input: nums = [1,2,3,4]
Output: 3
Explanation: We have 3 arithmetic slices in nums: [1, 2, 3], [2, 3, 4] and [1,2,3,4] itself.
Example 2:
Input: nums = [1]
Output: 0
Constraints:
1 <= nums.length <= 5000-1000 <= nums[i] <= 1000
Solution
class Solution {
fun numberOfArithmeticSlices(nums: IntArray): Int {
var sum = 0
var curr = 0
for (i in 2 until nums.size) {
if (nums[i] - nums[i - 1] == nums[i - 1] - nums[i - 2]) {
curr++
sum += curr
} else {
curr = 0
}
}
return sum
}
}