Reverse A String Using Stack Geeks For Geeks

 class Solution {

    

    public String reverse(String s){

        Stack<Character> stack=new Stack<Character>();

for(int i=0;i<s.length();i++){

stack.push(s.charAt(i));

}

StringBuffer sb=new StringBuffer();

while(!stack.isEmpty()){

sb.append(stack.pop());

}

String s1=sb.toString();

return s1;

    }

}

Approach:

We will add all the elements of the given string into the stack. After that, we will apply a while loop which will run till the stack becomes empty and the object of StringBuffer will append those characters.

In the end, we will convert the string buffer object to a string. 

TIME: O(N) [here N is the length of given string][GFG time: 0.2/1.5]

SPACE: O(1) [here we are simply appending the characters in the last and later converting object of StringBuffer into a string.]

Thanks for Reading 😇.