package main
import (
    "time"
    "fmt"
    "strings"
    "strconv"
)

func pop(stack *[]int) int {
    last := len(*stack) - 1
    ret  := (*stack)[last]
    *stack = (*stack)[:last]

    return ret
}

func main() {

    input := `10 20 100 + - 20 * DUP 10 20 + * =`;
    t := time.Now()

    for i := 0; i<10000; i++ {
        stack := []int{}

        for _, chunk := range strings.Split(input, " ") {
            switch (chunk) {
            case "+":
                stack = append(stack, pop(&stack) + pop(&stack))

            case "-":
                stack = append(stack, pop(&stack) - pop(&stack))

            case "*":
                stack = append(stack, pop(&stack) * pop(&stack))

            case "=":
                stack = append(stack, (map[bool]int{true: 1, false: 0})[pop(&stack) == pop(&stack)])

            case "DUP":
                stack = append(stack, stack[len(stack)-1])

            case "DUMP":
                fmt.Println(stack)

            default:
                val, _ := strconv.Atoi(chunk)
                stack = append(stack, val)
            }
        }
    }

    fmt.Printf("Go stack: %s\n", time.Since(t))
}