Leetcode #609: Find Duplicate File in System

func findDuplicate(_ paths: [String]) -> [[String]] {
    var dict = [String: [String]]()
    for path in paths {
        let components = path.components(separatedBy: " ")
        for i in stride(from: 1, to: components.count, by: 1) {
            var file = components[0] + "/"
            var str = Array(components[i])
            var index = 0
            while str[index] != "(" {
                file += "\(str[index])"
                index += 1
            }
            index += 1
            var content = ""
            while str[index] != ")" {
                content += "\(str[index])"
                index += 1
            }
            if let value = dict[content] {
                dict[content] = value + [file]
            } else {
                dict[content] = [file]
            }
        }
    }
    var answer = [[String]]()
    for key in dict.keys {
        if dict[key]!.count != 1 {
            answer.append(dict[key]!)
        }
    }
    return answer
}