Build error

Question

Guys, I’m making two mistakes and I don’t know how to fix it.

Follow the code below:

import java.io.*;
import java.util.*;

public class Pilha{

int elementos[];
int topo;

public Pilha(){
    elementos = new int[10000000];
    topo = -1;
}

public boolean empty(){
    return (topo == -1);
}

public int size (){
    return topo+1;
}

public int top(){
    return elementos[topo];
}

public int pop(){
    int e;
    e = elementos[topo];
    topo--;
    return e;
}

public void push(int e){
    topo++;
    elementos[topo] = e;
}

public static void main(String args[]) {
    Scanner in = new Scanner(System.in);
    String entrada = in.next();

    Pilha stack = new Pilha ();
    int var = entrada.length();

    int i = 0;

    while(i < var){
        if(!stack.empty() && stack.top() == '(' && entrada.charAt(i) == ')' ){
            stack.pop();
        }else stack.push(entrada.charAt(i));
        i++;
    }

    System.out.println(entrada.size() - stack.size());
}
}

 **2 errors
 lista1.java:4: error: class Pilha is public, should be declared in a file named Pilha.java
 public class Pilha{
        ^
 lista1.java:54: error: cannot find symbol
         System.out.println(entrada.size() - stack.size());
                                   ^
   symbol:   method size()
   location: variable entrada of type String**

PROBLEM LINK: here

Answer 1

lista1.java:4: error: class Stack is public, should be declared in a file named Stack.java

The Stack class is public, and must be declared in a file called Stack.java. ¹

lista1.java:54: error: cannot find Symbol System.out.println(input.size() - stack.size());

Symbol: method size()

Location: variable entry of type String

The variable entrada, of the kind String, does not have the method size(). ²

Therefore, to resolve these build issues, you should change the file name as requested, and use the length method for the size of String.