dreamolight

class Solution {
    func longestSubstring(_ s: String, _ k: Int) -> Int {
        let s = s.lowercased()

        var info = [Int](repeating: 0, count: 26)
        let chars = Array(s.utf8CString).map { Int($0 - "a".utf8CString.first!) }.filter{ $0 >= 0 }

        for c in chars {
            info[c] += 1
        }

dreamolight

- (void)controller:(NSFetchedResultsController *)controller
   didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath
     forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath
{
	if (![self isViewLoaded]) return;
    switch(type)
    {
        case NSFetchedResultsChangeInsert: