Discussion on Day 18: Queues and Stacks Challenge

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2 days ago+ 0 comments

Java Solution : Using StringBuilder instead of String or character array to manage space complexity.

StringBuilder stackVar =  new StringBuilder();
    int stackHead = -1;
    StringBuilder queueVar = new StringBuilder();
    int queueHead = 0;
    
    void pushCharacter(char c){
        stackHead++;
        stackVar.append(c);
    }
    
    void enqueueCharacter(char c){
        queueVar.append(c);
    }
    
    char popCharacter(){
        return stackVar.charAt(stackHead--);
    }
    
    char dequeueCharacter(){
        return queueVar.charAt(queueHead++);
    }

2 weeks ago+ 0 comments

function Solution() {
  this.stack = new Array();
  this.queue = new Array();
  this.pushCharacter = function (s) {
    this.stack.push(s);
  };
  this.enqueueCharacter = function (s) {
    this.queue.push(s);
  };
  this.popCharacter = function () {
    return this.stack.pop();
  };
  this.dequeueCharacter = function () {
    return this.queue.shift();
  };
}

1 month ago+ 0 comments

from queue import deque
class Solution:
    def __init__(self):
        self.stack=[]
        self.queue=deque()
    def pushCharacter(self,data):
        self.stack.append(data)
    def enqueueCharacter(self,data):
        self.queue.append(data)
    def popCharacter(self):
        return self.stack.pop()
    def dequeueCharacter(self):
        return self.queue.popleft()

1 month ago+ 0 comments

using namespace std; struct node { char c; node* next; }; node* Top=NULL; node* Front=NULL; node* tail=NULL; class Solution { //Write your code here public: void pushCharacter(char c) { node *link=new node; if(Top==NULL) { link->c=c; Top=link; link->next=NULL; } else { link->c=c; link->next=Top; Top=link; }

}
void enqueueCharacter(char c)
{
    node *link=new node;
    if(Front==NULL)
    {
        link->c=c;
        Front=link;
        link->next=NULL;
        tail=Front;
    }
    else 
    {
        link->c=c;
        tail->next=link;
        link->next=NULL;
        tail=link;
    }
}
char dequeueCharacter()
{
    char data;
    node* crr=Front->next;
    data=Front->c;
    delete(Front);
    Front=crr;
    return data; 
}

char popCharacter()
{
    char data;
    node* crr=Top;
    data=Top->c;
    Top=Top->next;
    delete(crr);
    return data;
}

};

1 month ago+ 0 comments

C# code:

class Solution {
    //Write your code here
    Queue<char> queue = new Queue<char>();
    Stack<char> stack = new Stack<char>();
    
    public void pushCharacter(char c)
    {
        stack.Push(c);
    }
    public char popCharacter()
    {
        return stack.Pop();
    }
    public void enqueueCharacter(char c)
    {
        queue.Enqueue(c);
    }
    public char dequeueCharacter()
    {
        return queue.Dequeue();
    }


    static void Main(String[] args) {
        // read the string s.
        string s = Console.ReadLine();
        
        // create the Solution class object p.
        Solution obj = new Solution();
        
        // push/enqueue all the characters of string s to stack.
        foreach (char c in s) {
            obj.pushCharacter(c);
            obj.enqueueCharacter(c);
        }
        
        bool isPalindrome = true;
        
        // pop the top character from stack.
        // dequeue the first character from queue.
        // compare both the characters.
        for (int i = 0; i < s.Length / 2; i++) {
            if (obj.popCharacter() != obj.dequeueCharacter()) {
                isPalindrome = false;
                
                break;
            }
        }
        
        // finally print whether string s is palindrome or not.
        if (isPalindrome) {
            Console.Write("The word, {0}, is a palindrome.", s);
        } else {
            Console.Write("The word, {0}, is not a palindrome.", s);
        }
    }
}

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