Issue with popping stack characters and saving them to a string - c++

Question

I have a bit of trouble with programming sometimes, but I'm generally alright and always have the issue of understanding the concept perfectly, but I hit a brick wall when I attempt to implement an actual program to perform an operation.
I have an assignment to work on, in which I must take an input string, read it character by character into a stack (using a linked list) and then pop that result out of the stack, store it to a new string and then compare the strings to determine if that particular input string is or isn't a palindrome.
The only issue so far that I seem to have ran into is (hopefully) at the very end of the program. When I attempt to pop each character off the stack and store them in a string individually, I get an issue where Visual Studio tells me: "error C2664: 'Stack::pop' : cannot convert parameter 1 from 'unsigned int' to 'char &'"
void Stack::pop(char &input_string) {
StackNode* temp;
if (isEmpty()) {
cout << "The stack is empty." << endl;
}
else {
input_string = top->value;
temp = top->next;
delete top;
top = temp;
}
}
int main () {
Stack stringStack;
string input_string;
string reverse_input;
cout << "Input the desired string to determine if it is a palindrome or not. No spaces please." << endl;
cin >> input_string;
for (unsigned int i=0; i < input_string.length(); i++) {
stringStack.push(input_string[i]);
}
while (!stringStack.isEmpty()) {
for (unsigned int j=0; j < input_string.length(); j++) {
stringStack.pop(j) = reverse_input[j];
}
}
if (reverse_input == input_string) {
cout << "Your input is a palindrome!" << endl;
}
else {
cout << "Your input was not a palindrome, try again!" << endl;
}
system ("PAUSE");
}
I realize that it is telling me that I cannot pass j into the pop function to pop out the values because the pop function I have declared is expecting a char value.
Could this be remedied by changing the input to the pop function to an integer, and then using the pop function to return the char value instead?
I am excluding all other function of the cpp file other than the pop function and the main execution function, let me know if you need to see another part for some reason.
Thanks in advance for the help. It is much appreciated.

Answer 1

In this part:
while (!stringStack.isEmpty()) {
for (unsigned int j=0; j < input_string.length(); j++) {
stringStack.pop(j) = reverse_input[j];
}
}
Assuming that the goal is to take the element at the top of the stack with pop and add it at the end of the string reverse_input so that the resulting reverse_input would be the reverse of input_string, there is one too many loops.
for( unsigned int j = 0; !stringStack.isEmpty() ; j++ ){
//Code Here
}
Or:
while( !stringStack.isEmpty() ){
//Code Here
}
Also stringStack.pop(j) = reverse_input[j]; isn't actually assigning anything, as pop is a void function.
One alternative is the following:
Modify the pop so that it returns the char element at the top.
char Stack::pop() {
StackNode* temp;
char mychar = '\0';
if (isEmpty()) {
cout << "The stack is empty." << endl;
}
else {
mychar = top->value;
temp = top->next;
delete top;
top = temp;
}
return mychar;
}
Then:
reverse_input = ""; //To make sure it is empty
while( !stringStack.isEmpty() ){
reverse_input += stringStack.pop();
}