Florian Valeye’s Post

Today after seeing the recording of Topic Tries in NextLeap. Q. Implement Trie (Prefix Tree) A trie (pronounced as "try") or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker. Implement the Trie class: Trie() Initializes the trie object. void insert(String word) Inserts the string word into the trie. boolean search(String word) Returns true if the string word is in the trie (i.e., was inserted before), and false otherwise. boolean startsWith(String prefix) Returns true if there is a previously inserted string word that has the prefix prefix, and false otherwise. Example: Input ["Trie", "insert", "search", "search", "startsWith", "insert", "search"] [[], ["apple"], ["apple"], ["app"], ["app"], ["app"], ["app"]] Output [null, null, true, false, true, null, true] Code: class Trie {     class Node {         Node [] childs;         boolean isEnd;         Node(){             childs = new Node[26];             isEnd = false;         }     }     final private Node root;     public Trie() {         root = new Node();     }         public void insert(String word) {         Node curr = root;           for(int i = 0;i<word.length();i++){             char ch = word.charAt(i);                     if(curr.childs[ch - 'a'] == null){                 curr.childs[ch - 'a'] = new Node();             }             curr = curr.childs[ch - 'a'];         }                 curr.isEnd = true;     }           public boolean search(String word) {         Node curr = root;           for(int i = 0;i<word.length();i++){             char ch = word.charAt(i);                         if(curr.childs[ch - 'a'] == null){                  return false;             }             curr = curr.childs[ch - 'a'];         }         return curr.isEnd;     }           public boolean startsWith(String prefix) {           Node curr = root;           for(int i = 0;i<prefix.length();i++){             char ch = prefix.charAt(i);                         if(curr.childs[ch - 'a'] == null) {                 return false;             }             curr = curr.childs[ch - 'a'];         }         return true;     } } This question are easy because I saw the recording of Tries. Tries concept and qeustion are explained by Mohammad F. in classes. In session he solve many questions of Tries so I understand how to solve. #nextleapdsachallenge #nextleapdsachallenge #nextleapdsafellowship #nextleap

Hello everybody, Well as promised let's continue with the topic "Typecasting and comments in CPP" 😊 As I have already mentioned about two types of typecasting (widening/automatic and narrowing/user). 👩💻 Widening typecasting is the one in which there's no data loss as conversion of smaller data type to bigger data type takes place, like char to int, int to double, etc. Let's see it by example-> #include<iostream> using namespace std; int main(){ char ch='A'; int num=ch; ->Here, we are converting variable ch which is of char data type into integer data type(we don't need to write anything for conversion, this conversion is done automatically by compiler for widening typecasting.) cout<<num<<endl; double myNum=num; ->Here, we are converting variable num which is of integer data type into double data type. cout<<myNum;} ✌ 👩 (well, we are done with implicit typecasting) Now, comes the second type of typecasting explicit/narrowing, here data loss can happen as conversion of bigger data type to smaller data type takes place,so memory allocation will also be smaller. Now, let's see it by example-> #include<iostream> using namespace std; int main(){ int num=18;char ch=(char)num ; ->Here, we are converting variable num which is of integer data type into char data type. cout<<ch<<endl; double myNum=687555.6757; int num1=(int)myNum ->Here, we are converting variable myNum which is of double data type into int data type. cout<<num1;} Well, now we are done with our typecasting topic completely. 🤝 😀 Now, let's start with another useful topic which actually is very important while coding and that's comments. So, what actually are comments?🙄 🤔 Basically comments are something which we usually add in our program to improve the understanding of code , for example I am want to write a code which print 2numbers and then again multiplying 2 numbers.So, I can write a comment where I am adding those numbers and other for multiplying. Comments don't get compiled in a program, they are just used so that any other person or a programmer himself gets to know what particular code is written for which thing, basically used in complex programs. Comments are also of 2 types-> 1)Single line comments-> When, we are writing a single sentence or short comment , we use single line comment , denoted by //. eg.> //Using pi=3.14; here, I have used single line comment followed by //. 2)Multiline comments-> Whenever we require to add multiple lines in a program for better understanding , we use multi line comments. denoted by /*Please write your comment here*/, starts with /* and ends with*/. So, this was the simple topic of CPP i.e." comments and typecasting. Now, here comes a program which shows typecasting and comments in a better way. Thanks to my instructor Jasmeen kaur,Mohammad F. and NextLeap . #nextleapdsachallenge

Stack Stack is a derived Data Structure which uses LIFO (Last in First out) format.It helps to solve so many complex problems like parenthesis problems , next greater element etc. we can implement multiple operation like push, pop, size and getTop in Stack. Push : it is used to insert the element at the top of the stack. Pop : it is used to remove the top element from the stack . size : it is used to check how many elements has been inserted into the stack. getTop: it is used to get the top element from the stack without popping it. Implementation : There are two ways to implement Stack Data structure. a. Arrays : It is an easier approach to implement stack but it has limited memory and it has also costlier operations because we have to shift the element in the whole array whenerver we have to perform push and pop operation. b. LinkedList : it is quite complex to implement stack via linked list but it is easier to perform push and pop operation via Linked List Implementation via array class Stack{ array =[]; size(){ return this.array.length; } getTop(){ if(this.size()==0){ return -1; } else{ return this.array[0] } } push(value){ this.array.splice(0,0,14) } pop(){ if(this.size()==0){ return -1; } else{ return this.array.shift(); } } } Implementation using LinkedList class Node{ constructor(data){ this.data=data; this.next=null; } } class LStack { constructor(){ this.top=null; } size(){ if(this.top==null){ return 0; } else{ let current = this.top; let total=0; while(current){ total=total+1; current=current.next; } return total; } } getTop(){ if(this.top==null){ return -1; } else{ const value = this.top.data; return value; } } push(value){ const node = new Node(value) if(this.top==null){ this.top=node; } else{ node.next= this.top; this.top = node; } } pop(){ if(this.top==null){ return -1;} } else{ const value = this.top.data; this.top= this.top.next; return value ; } } #stack #datastructures #arrays #linkedlist #programmingtips