Reversing a string using stack

[starletcharmed]

Hi,
can anyone help me with my code? Im trying to reverse my string using stack... but when it compiles and put in a string and press enter... nothing happens...
Any suggestions?

#include <iostream>
#include<stack>
#include<string>

using namespace std;

int main()
{    
stack <string> s;
string a;

cout << "Enter: " << endl;

while(getline(cin, a) && a != "\n")
{
       s.push(a);
}


while(!s.empty())
{
      cout << s.top();
      s.pop();
}

    cout << endl;
    system("pause");
    return 0;
}

[Narue]

Most of your problems can be fixed by using a stack of characters instead of strings:

#include <iostream>
#include <stack>

using namespace std;

int main()
{    
  stack<char> s;
  char a;

  cout << "Enter: " << endl;

  while ( cin.get ( a ) && a != '\n' )
    s.push(a);

  while ( !s.empty() ) {
    cout << s.top();
    s.pop();
  }

  cout<<'\n';
}

[starletcharmed]

Wow, that was quick! Thanks a lot :)

[gregorynoob]

also can be done recursively..but stack almost equals recursion... for example:

#include <iostream>
#include <string>
using namespace std;

void do_the_stuff() {
     char c; c = getchar();
     if( c == '\n' ) return;
     do_the_stuff();
     putchar( c );
}

int main( void )
{
    cout << "Enter:" << "\n";
    do_the_stuff();   
    return 0;
}

[sidatra79]

I have another proposition for a recursive solution:

#include <iostream>
#include <string>

std::string GetName(); // String to get user's name.
void reverseString(std::string str);

int main()
{
	std::string name;
	name=GetName();
	std::cout<<"The string is: "<<name<<std::endl;
	std::cout<<"Now the reverseString function is going to reverse the string: "<<std::endl;
	reverseString(name);
	return 0;
}

std::string GetName()
{
	std::string name;
	std::cout << "What is your name?" << std::endl;
	std::cin >> name;
	return name;
} 
//The recursive function
void reverseString(std::string str)
{
	if (str=="")//the base case
		return;
	else //the recursion step
	{
		reverseString(str.substr(1));			
		std::cout<<str.at(0);
	}
}

The recursive function in the recursive step calls itself to display the rest of the string before displaying the first character in the current string argument. This fact causes a delay on displaying the first character in the current string until all characters in the rest of the string are first displayed.

[d_a_y_o]

Here is an easier version. It does the same thing.

#include <stack>
#include <string>

using namespace std;

 int main
 {
    string words;//stores separate words
    stack<string> sentence;//stores all the words

    cout << "Please type the word lol at the end of your sentence\n\n";
    cout << "Please Enter a Sentence: ";


    while(words != "lol")
    {
        cin >> words;
        sentence.push(words);
    }

    cout << "\n";
    cout << "The Sentence contains " << sentence.size() << " words" << endl; 
    cout << "\n";

    while(!sentence.empty())
    {
       cout << sentence.top() << " ";
       sentence.pop();
    }

    system("pause>null"); 
    return 0;
}