56. Merge Intervals

LCMergeIntervals.swift

/* 
 * Definition for an interval.
 * public class Interval {
 *   public var start: Int
 *   public var end: Int
 *   public init(_ start: Int, _ end: Int) {
 *     self.start = start
 *     self.end = end
 *   }
 * }
 */
class Solution {
    func merge(_ intervals: [Interval]) -> [Interval] {
        var mergedIntervals = [Interval]()
        //intervals.sorted(by: {(interval1: Interval, interval2: Interval) in return interval1.start < interval2.start})
        for interval in intervals.sorted(by: {$0.start < $1.start}) {
            if mergedIntervals.count == 0 || mergedIntervals.last!.end < interval.start {
                mergedIntervals.append(interval)
            } else {
                mergedIntervals.last!.end = max(interval.end, mergedIntervals.last!.end)
            }
        }
        return mergedIntervals
    }
}