백준 Kotlin 10773번 : 제로

https://www.acmicpc.net/problem/10773

10773번: 제로

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import java.util.Scanner
import java.util.Stack

fun main() {
    val sc = Scanner(System.`in`)

    val K = sc.nextInt()
    val stack = Stack<Int>()
    for (i in 0 until K) {
        var num = sc.nextInt()
        if (num == 0)
            stack.pop()
        else
            stack.push(num)
    }
    println(stack.sum())
}