LeetCode in Kotlin
1051. Height Checker
Easy
A school is trying to take an annual photo of all the students. The students are asked to stand in a single file line in non-decreasing order by height. Let this ordering be represented by the integer array expected where expected[i] is the expected height of the ith student in line.
You are given an integer array heights representing the current order that the students are standing in. Each heights[i] is the height of the ith student in line (0-indexed).
Return the number of indices where heights[i] != expected[i].
Example 1:
Input: heights = [1,1,4,2,1,3]
Output: 3
Explanation:
heights: [1,1,4,2,1,3]
expected: [1,1,1,2,3,4]
Indices 2, 4, and 5 do not match.
Example 2:
Input: heights = [5,1,2,3,4]
Output: 5
Explanation:
heights: [5,1,2,3,4]
expected: [1,2,3,4,5]
All indices do not match.
Example 3:
Input: heights = [1,2,3,4,5]
Output: 0
Explanation:
heights: [1,2,3,4,5]
expected: [1,2,3,4,5]
All indices match.
Constraints:
1 <= heights.length <= 1001 <= heights[i] <= 100
Solution
class Solution {
fun heightChecker(heights: IntArray): Int {
var heightDiff = 0
val count = IntArray(101)
val actualLine = IntArray(heights.size)
for (height in heights) {
count[height]++
}
var heightLength = 0
for (i in count.indices) {
if (count[i] > 0) {
for (j in 0 until count[i]) {
actualLine[heightLength] = i
heightLength++
}
count[i] = 0
}
}
for (i in heights.indices) {
if (actualLine[i] != heights[i]) {
heightDiff++
}
}
return heightDiff
}
}