Reverse String using Stack

 Write a function that reverses a string. The input string is given as an array of characters s.


You must do this by modifying the input array in-place with O(1) extra memory.


 


Example 1:


Input: s = ["h","e","l","l","o"]

Output: ["o","l","l","e","h"]

Example 2:


Input: s = ["H","a","n","n","a","h"]

Output: ["h","a","n","n","a","H"]



class Solution {
    public void reverseString(char[] s) {
       

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

         for(char c:s)
         {
            st.push(c);
         }

         int i=0;
         while(!st.empty())
         {
            s[i++]=st.pop();
         }
    }
}

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