Rahul Pandey rahularity

Subarray Problems

Linked Lists

Depth First Search

Used to traverse a tree or a graph in depth first manner

// globally we have a Graph G of lets say 100 nodes
vector<int>* G = new vector<int>[100];
// globally we also have a vector to store weather or not a node has been visited
vector<bool> visited(100, false);

/*
	===================== GCD (GREATEST COMMON DIVISOR) =====================
	
	FINDING THE GREATEST COMMON DIVISOR EFFICIENTLY USING EUCLID'S FORMULA.
				GCD(a,b) = GCD(b, a%b)
	
*/

int GCD (int a, int b){

Angular

Angular uses TypeScript

Typescript is basically the superset of Javascript which gives (Classes, Interfaces, Types etc.). It is strongly typed language. It cannot be run in the browser, it gets compiled to javascript.

Module Introduction:

Angular serves the index.html page as the single page for the project

Kotlin Null Safety

Null Safety
- Safe Call Operator ( ?. )
- Elvis operator ( ?: )
- Not-null assertion operator ( !! )

Null Safety

A variable that doesn't refers to anything, refers to null. Null is a keyword to allow a variable refer to nothing or to check if it exists (comparison can be done with == or !=)

Kotlin Programming (Basics and Important)

How To Work With Multiple Github Accounts on a single Machine

Let suppose I have two github accounts, https://github.com/rahul-office and https://github.com/rahul-personal. Now i want to setup my mac to easily talk to both the github accounts.

NOTE: This logic can be extended to more than two accounts also. :)

The setup can be done in 5 easy steps:

Steps:

Step 1 : Create SSH keys for all accounts
Step 2 : Add SSH keys to SSH Agent

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	/*
	Read the problem statement from here: https://www.spoj.com/problems/AGGRCOW/
	*/

	#include<bits/stdc++.h>
	using namespace std;

	bool isPossible(int arr[], int n, int interval, int C){
	C--;
	int start = arr[0];

	/*
	Given two words Word1 and Word2 find minimum number of operations required to convert Word1 to Word2.
	You have the following 3 operations permitted on a word:
	Insert a character
	Delete a character
	Replace a character
	*/

	// minimum of three numbers
	int min(int x, int y, int z)