You get a string with operation as input:

if it is a number push it to stack
if it is "DUP", then duplicate the one one top and push it to the stack
if it is "POP" then remove the one on top
if it is "+" add the two numbers on top of the stack and replace both with the result of the addition
if it is "-" then minus the two numbers on top (the second minus the first) of the stack and replace both with the result of the subtraction
if an error occurs, e.g. not enough numbers to add/subtract/pop, then return -1

Examples:

Input: "3 DUP 5 - -"
Output: -1

Input: "13 DUP 4 POP 5 DUP + DUP + -"
Output: 7

Input: "5 6 + -"
Output: -1

Question

You get a string with operation as input:

        if it is a number push it to stack
        if it is "DUP", then duplicate the one one top and push it to the stack
        if it is "POP" then remove the one on top
        if it is "+" add the two numbers on top of the stack and replace both with the result of the addition
        if it is "-" then minus the two numbers on top (the second minus the first) of the stack and replace both with the result of the subtraction
        if an error occurs, e.g. not enough numbers to add/subtract/pop, then return -1

Examples:

Input: "3 DUP 5 - -"
Output: -1

Input: "13 DUP 4 POP 5 DUP + DUP + -"
Output: 7

Input: "5 6 + -"
Output: -1

GitHub

Pergunta de entrevista da empresa GitHub

Empresas seguidas

Buscas de vagas