릿코드 1863. Sum of All Subset XOR Totals 코틀린

모든 서브셋을 구하고 모든 서브셋의 xor값의 합을 리턴
걍시키는대로하면됨

정답

class Solution {
    fun subsetXORSum(nums: IntArray): Int {
        val numList = nums.toList()
        val subsetList = numList.subset()
        var res=0
        for (i in subsetList){
            if (i.isEmpty()) continue
            if(i.size==1){
                res+=i[0]
                continue
            }
            var tempRes=i[0]

            for (j in i.subList(1,i.size)){
                tempRes=tempRes xor j
            }
            res+=tempRes
        }
        return res
    }
}



fun List<Int>.subset(): List<List<Int>> {
    val res = mutableListOf<List<Int>>()

    for (i in 0 until (1 shl this.size)) {
        val list = mutableListOf<Int>()
        for (j in this.indices) {
            if (i and (1 shl j) != 0) {
                list.add(this[j])
            }
        }

        res.add(list)
    }
    return res
}