[TIL],[프로그래머스],[롤케이크 자르기],[Swift]

import Foundation

func solution(_ topping:[Int]) -> Int {
    
    var array1:[Int:Int] = [:]
    var array2:[Int:Int] = [:]
    var count = 0
    
    for i in topping{
        if array1[i] == nil{
            array1[i] = 1
        } else {
            array1[i]! += 1
        }
    }
    
    for i in topping{
        if array1[i]! == 1{
            array1[i] = nil
        } else {
            array1[i]! -= 1 
        }
        
        if array2[i] == nil{
            array2[i] = 1
        } else {
            array2[i]! += 1
        }
        
        if array1.keys.count == array2.keys.count{ count += 1 }
    }
    return count
}