Stiva inversare sir caratere

#include <string.h>
#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;

class Stiva {
    int max;
    char *t;
    int top;
public:
    Stiva(int max) {
        this->max= max;
        this->t = new char[max];
        this->top = -1;
    }

    void push(char c) {
        if(top < max-1){
            t[++top]=c;
        } else {
            cerr<<"Eroare. Depasire capacitate\n";
            exit(1);
        }

    }

    char pop() {
        return t[top--];
    }

    bool isEmpty() {
        /*
        if(top == -1)
            return true;
        else
            return false;
        */
        return top == -1;


    }

    bool isFull() {
        return top == max-1;
    }


};

int main() {

    /* Varianta cu cu tablou de caractere */
    /*
     int i;
     char input[100]="abcde";
     char output[100];
     Stiva stiva(strlen(input));


     for(i=0;i<strlen(input);i++){
        stiva.push(input[i]); // iau fiecare caracter din sirul de intrare si il pun in stiva.
     }

     i=0;
     while (!stiva.isEmpty())  {
            output[i]= stiva.pop();
            i++;
     }
     output[i]='\0';
     cout<<output;

    */

    string input = "abcde";
    string output;
    Stiva stiva(input.length());
    for(int i=0; i<input.length(); i++) {
        stiva.push(input[i]); // iau fiecare caracter din sirul de intrare si il pun in stiva.
    }

    output = "";
    while (!stiva.isEmpty())  {
        output = output + stiva.pop(); //caracterul scos din stiva cu pop() e adaugat la output
    }
    cout<<output;

}