RomanInteger.kt

class Solution {
    fun romanToInt(s: String): Int {
        val specialCases=hashMapOf<String,Int>(
            "IV" to 4,
            "CM" to 900,
            "XC" to 90,
            "IX" to 9,
            "XL" to 40,
            "CD" to 400
        )
        val map=hashMapOf<String,Int>(
            "I" to 1,
            "V" to 5,
            "X" to 10,
            "L" to 50,
            "C" to 100,
            "D" to 500,
            "M" to 1000
        )

        var sum=0
         var i=0
        while(i<s.length){
            val current=s[i].toString()
            when(current){
                "I",
                "X",
                "C"->{
                    if(i<s.length-1){
                        val next=s[i+1].toString()
                        if(specialCases.containsKey(current+next)){
                            sum+=specialCases[current+next]!!
                            s.replace(current+next,"")
                            i+=2
                        }else{
                            sum+=map[current]!!
                            s.replace(current,"")
                             i++
                        }
                    }else{
                        sum+=map[current]!!
                        s.replace(current,"")
                         i++
                    }
                }
                else->{
                    i++
                    sum+=map[current]!!
                    s.replace(current,"")
                }
            }
        }
        return sum
    }
}