Solving https://leetcode.com/problems/my-calendar-i/

Solution.kt

class MyCalendar() {
    data class Interval(val start: Int, val end: Int) {
        fun overlaps(other: Interval) : Boolean = (
            (start <= other.start && other.start <  end) ||
            (start <  other.end   && other.end   <= end) ||
            (start >= other.start && other.end   >= end)
        )
    }
    
    val intervals = mutableListOf<Interval>()
    
    fun book(start: Int, end: Int): Boolean {
        val toBook = Interval(start, end)
        if (intervals.any{ it.overlaps(toBook)}) {
            return false
        }
        
        intervals.add(toBook)
        return true
    }
}