66. The algorithm is simple and swift string of a single character

Given a string, find its first non-repeating characters, and returns its index. If not, it returns -1.

Case:

s = "leetcode"
return 0.

s = "loveleetcode",
return to 2.
 

Note: You can assume that the string contains only lowercase letters.

solution:

    func firstUniqChar(_ s: String) -> Int {
         for item in s {
            if let index = s.firstIndex(of: item)  {
                if  index == s.lastIndex(of: item) {
                    return index.encodedOffset
                }
            }
        }
        
        return -1
    }