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  1. Prepare
  2. Tutorials
  3. 30 Days of Code
  4. Day 18: Queues and Stacks
  5. Discussions

Day 18: Queues and Stacks

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697 Discussions

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  • nhattan214
     + 0 comments

    Python 3

    class Solution:
    def __init__(self):
        self.stack=[]
        self.queue=[]
    def pushCharacter(self,char):
        self.stack.append(char)
        return self.stack
    def popCharacter(self):
        return self.stack.pop()
    def enqueueCharacter(self,char):
        self.queue.append(char)
        return self.queue
    def dequeueCharacter(self):
        return self.stack.pop(0)
    # Write your code here

# read the string s
s=input()
#Create the Solution class object
obj=Solution()   

l=len(s)
# push/enqueue all the characters of string s to stack
for i in range(l):
    obj.pushCharacter(s[i])
    obj.enqueueCharacter(s[i])
    
isPalindrome=True
'''
pop the top character from stack
dequeue the first character from queue
compare both the characters
''' 
for i in range(l // 2):
    if obj.popCharacter()!=obj.dequeueCharacter():
        isPalindrome=False
        break
#finally print whether string s is palindrome or not.
if isPalindrome:
    print("The word, "+s+", is a palindrome.")
else:
    print("The word, "+s+", is not a palindrome.")

  • rebecca_alia_ro1
     + 0 comments

    Javascript

    class Solution{
  
  constructor(){
    this.stack = [];
    this.queue = [];
  }
  
  pushCharacter(char){
    //store original array here
    this.stack.push(char);
  }  
    
  enqueueCharacter(char){
    //store reverse array here
    this.queue.unshift(char);
  }
  
  popCharacter(){
    //return first character from stack
    return this.stack.pop();
  }
  
  dequeueCharacter(){
    //return first character from queue
    return this.queue.pop();
  }
  
}

  • illogicalsleepi1
     + 1 comment
    class Solution:
    def __init__(self):
        self.stack=[]
        self.queue=[]
    def pushCharacter(self,x):
        self.stack.append(x)
    def enqueueCharacter(self,x):
        self.queue.insert(0,x)
    def popCharacter(self):
        return self.stack.pop()
    def dequeueCharacter(self):
        return self.queue.pop()

  • dadougla
     + 0 comments

    There is a PHP error with the code provided.

    PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in Solution.php on line 34

  • cpharshadeep
     + 0 comments

    code in java 15 class solution {

    ArrayDeque ad1=new ArrayDeque(); //for stack ArrayDeque ad2=new ArrayDeque(); //for queue

    void pushCharacter(char ch)
{
    ad1.push(ch);

}
void enqueueCharacter(char ch)
{
    ad2.add(ch);
}


char popCharacter()
{
    return (char)ad1.pop();
}

char dequeCharacter()
{
    return (char)ad2.poll();
}





public static void main(String[] args) {

    Scanner sc=new Scanner(System.in);
    String s=sc.nextLine();
    Solution p=new Solution();
    for(int i=0;i<s.length();i++)
    {
        p.pushCharacter(s.charAt(i));
        p.enqueueCharacter(s.charAt(i));
    }

    boolean b=true;
    for(int i=0;i<s.length()/2;i++)
    {
        if(p.popCharacter()!=p.dequeCharacter())
        {
            b=false;
            break;
        }
    }
    if(b)
    {
        System.out.println("The word, "+s+", is a palindrome.");
    }
    el
            }se
    {
    System.out.println("The word, "+s+", is not a palindrome.");
    }
}