Last Updated: 12 Feb, 2021
Kevin’s stack problem
Easy
Asked in companies
Kevin has recently learned the concept of “STACK”. During his practice, he got stuck in a problem where he has to reverse a string ‘S’ using a stack. So, he appoints you to help him in reversing the string ‘S’. All you have to do is to find the reversed string.
Please reverse the string using a stack so that Kevin gets to know where he is getting wrong after seeing your solution. It is guaranteed that strings will only be composed of English alphabets.
Input Format:
The first line contains a single integer ‘T’ representing the number of test cases.
The first line of each test case will contain a string ‘S’.
Output Format:
For each test case, return the reversed string.
Output for every test case will be printed in a separate line.
Note:
You do not need to print anything, it has already been taken care of. Just implement the given function.
Constraints:
1 <= T <= 10
1 <= |S| <= 10^4
Time limit: 1 sec
Approaches
The basic idea is to push the whole string into a stack (character by character) and then take off each character from the stack one by one. The steps are as follows:
- Iterate through ‘S’.
- Push each character into the stack.
- Keep removing the top character from the stack until the stack becomes empty. Append each drawn character to the new string.
- Return the new string.