253. Meeting Rooms II

//方法一 ： 由于我们并不需要输出一个skyline, 只需要max. 所以只需要start， end数组并且排序

func minMeetingRooms(_ intervals: [Interval]) -> Int {
        var start = intervals.map{ $0.start}.sorted()
        var end = intervals.map{ $0.end }.sorted()
        var i = 0
        var j = 0
        var res = 0
        var curr = 0
        while i < start.count && j < end.count{
            if start[i] < end[j]{
                curr += 1
                i += 1
                res = max(res, curr)
            }else{
                curr -= 1
                j += 1
            }
        }
        return res
    }

// 方法二：合并成一个大的array 排序

    func minMeetingRooms(_ intervals: [Interval]) -> Int {
        var points = [(Int, Bool)]() // index, isstart
        for interval in intervals{
            points.append((interval.start, true))
            points.append((interval.end, false))
        }
        points.sort{
            if $0.0 == $1.0 {
                return !$0.1 ? true : false
            }
            return $0.0 < $1.0
        }
        var res = 0
        var curr = 0
        for p in points {
            if p.1 {
                curr += 1
                res = max(res, curr)
            }else{
                curr -= 1
            }
        }
        return res
    }