solve.swift

import Foundation
import Glibc
import extratypes // this library contains declarations of types from the task

public func solution(_ T : Tree?) -> Int {
  var max = 0
  guard let T = T else { return 0 }
  T.l?.calculate(&max, 1)
  T.r?.calculate(&max, 1)

  return max
}

extension Tree {
  func calculate(_ max: inout Int, _ depth:Int) {
    if(depth > max){ max = depth }
    if(self.l != nil){
      l!.calculate(&max, depth+1)
    }
    if(self.r != nil){
      r!.calculate(&max, depth+1)
    }
  }
}