剑指 Offer II 074. 合并区间

排序。然后重合的区间进行合并

func merge(_ intervals: [[Int]]) -> [[Int]] {
        let length = intervals.count
        if length <= 1 {
            return intervals
        }
        
        let sortArray = intervals.sorted(by: {$0[0] < $1[0]})
        var endArray = Array<[Int]>()
        
        for  array in sortArray {
            
            let left = array[0] ,right = array[1]
            let length = endArray.count
            var last =  length >= 1 ? endArray[length - 1] : [-1,-1]
            if length == 0 || last[1] < left {
                endArray.append(array)
            }else {
                last[1] = max(last[1], right)
                endArray[length - 1] = last
            }
        }
        
      return endArray
    }