Leetcode #581: Shortest Unsorted Continuous Subarray

Solution 1: Sorting

func findUnsortedSubarray(_ nums: [Int]) -> Int {
    var sortedAr = nums.sorted()
    var start = -1
    var end = -1
    for i in stride(from: 0, to: nums.count, by: 1) {
        if nums[i] != sortedAr[i] {
            if start == -1 {
                start = i
            } else {
                end = i
            }
        }
    }
    return start == -1 ? 0 : end - start + 1
}