class Solution { func eraseOverlapIntervals(_ intervals: [[Int]]) -> Int { let intervals = intervals .map { ($0[0], $0[1]) } .sorted { l, r in l.1 < r.1 } var lastEnd: Int = .min var erased = 0 for (start, end) in intervals { if start >= lastEnd { lastEnd = end } else { erased += 1 } } return erased } }