DSA stands for Data Structures and ALgorithms

Being good at DSA should mean that you are good at use data structures and algorithms to solve a problem in most optimal way possible .
It is usefull as it increases the thinking ability of a human to solve a problem in the given resources / utilizing the given resources to meet the requirements and also have a good performance.

This page teaches you - I wouldn't say all - but something that would be enough to last a human life time |
In order to get better at programming logics I use OOPs as well |
learn shell scripting BTW , it drastically increases your programming power |
what is shell scripting ? , bruh are you using windows [buhahaha , That's what few linux user would say but, I am different I do like windows for what it is - if someone wants something else they can have something else. What I meant was - are you using buttons ? I am still unemployed and I might also be able to give interviews to microsoft so I guess I shouldn't stay stuff like that .No offence to windows I wanted to say / I meant GUI . BTW imagine - me an arch linux user giving interview to microsoft, I really like windows - its good and stuff , Its support to run certain executables is the best feature like games . And there are other good things like security , anti virus features etc.]?

To make the learning the way it has to be and not by some outdated types like sitting in a room and just using pen paper - I introduce the idea of shinobi ranking ,
You have to compete studying through one level to reach a level / unlock a level that's above it - obv there are no restrictions / constraints - it is just a convention - if you cheat , you still know where you stand |
passing level would be if you understood everything till the level of a KAGE

Genin [naruto] level on the header show level and show images of characters to jump to levels

Analyse the Problem

Understand the problem. Take a second to recall whatever you learnt in relevance with the problem

Deduction

Think of the specific problem statement -> break it down to simpler parts -> think of the solution to simpler parts -> combine the solution

Flowchats

Most important part of problem solving is on paper . . . that is where 80% of the problem is solved from easiest to the most difficult problem

Always document the process

Helps you keep going throught the topics like a Flow !

Basic problems

parity checker

largest of 3 numbers

primality

largest of 3 numbers

Java

Java is platform independent and hence its class files can be circulated across machines without tampering

![WARNING] Though JDK is convert those class executables into machine code . A higher lower version of JDK cannot convert a .class file into machine code that was compiled by a higher version of JDK

JDK = JRE+Compiler+docs

JRE contains JVM

Different mahcines has different JVMs but JDK is smart enough to compile other machine .class into machine code

Java does support foward reference

C doesn't

DATATYPE

characters are stored in the form of ASCII values

Conversion [typeCasting]

Implicit conversion is done from type of lower or equal size to higher size of type.

Narrowing conversion the upper one - explicitly declare it , if you want the conversion , else just show it in desired form while printing (char)a where a is an int

int i=0;
    float p=i;
  

If you want to convert to lower size type you need to explicitly mention that

int i=0;
    char p=i;
  

int i=0;
    char p=(char)i
  

Precedence of operators in JAVA

operatorPrecendenceJava
moregraphical

Scanner

scanner




commonly used scanner

Scope of Variables

when variables are initialized inside a loop, its only available there not even outside the loop in the same function

#include<stdio.h>

int main(){
int a=10;
if(a>0){
int b=20;
}

printf("%d\n%d",a,b);
}
  

/ document the practise problem that is the patterns ones and etc in some squid game manner like how the pink soldiers ask for square or triangle etc....

Bitwise operators

int a=10;
int b=2;

System.out.println(a&b);
System.out.println(a|b);
System.out.println(a^b);
System.out.println(~a);// "~" this is the complement operator
System.out.println(a << 2); // left shift by 2 raised to 2 , as it is converted into binary that is
essentailly "a*(2**2)". <br> For ex - 6 << 2 is
// 6 - 0000110
// 2 left shifts makes - 0011000 = 24
// which is 6*(2**2), 6*4=24
System.out.println(a >> 2); // right shift i.e. -4
  

Convert the values of variables to binary then perform the specified operations and you will get the result.
Make use of few properties such as : a^a=0, since all the bits are same
a^0=a.

Loops / functions

Pratise this for better understanding of loops

++i , increments before using i

i++ , increments later

mostly usefull in print statements
since

if you do

i=5;
    i++;
    // [or] ++i;
    printf("%d",i);
    // There will be no change
  

in for loops

1. initialises the var , no matter what. The first value of the var is the value initialised in the parameters of the loop [cuz point 4]

2. checks the condition ; if true goes into the body

3. executes the body

4. now performs what ever opetaion is mentioned in the for loop

5. goes to step 2

![NOTE] the comparision step in a for loop is done n+1, the last time is for the rejection take the following as an example:

 
int i=1;
for(;i<n;i++)
System.out.println(i);// this prints till 5
System.out.println(i); // this prints till 6 , cuz i++ , i got incremented but rejected by the condition step ,
though it is still a function variable and not a loop variable , the trace is kept by the function and the
incremented value is printed
  

int a=60,b=80;

if(a++ >60 && b++ > 80 ){
System.out.println("Inside if");
}
else{
System.out.println("Inside else");
}

System.out.println("a: "+a+" "+"b: "+b);
  

Inside else
    a: 61 b:80
  

since a is incremented after being processed 60 is not > 60 so inside else
logical operators uses short-circuit and hence since first part is taken as not true the remaining part is unnecessary to evaluate and hence skips that part - which essentially skips the part where b is incremented and b remains 80!

Patterns

Square patterns

Trianlge

characters

pyramid

Pass by value

public static void increment(int n){
n++
}

// in main

increment(n);

// n won't increment since n's value is passes and not n itself and hence n's value is incremented and
not n , to be more precise the local varible of the increment function was incremented
  

The fix to this is by using pointers in C

Function Overloading

public static int sum(int a, int b){
return a+b;
}
public static double sum(int a, int b){// not possible , same parameters are already defined in another function of
the same name
return a+b;// though if this was the only function make sure to pass int to it and it will return the double
}
public static int sum(int a){ // works
return a;
}
  

chunin level [add genin pic at the start of this page] [for chunin add chunin pics] -- mention chunin , jounin , Anbu , S ranked , KAGE , Sanin , WarHeroes [obito-madara-might guy] , unknown potential [sakumo hatake, shisui, minato] , Itachi/Light

add takamura somewhere as a level in website

LINEAR DATA | NON LINEAR DATA

LINEAR DATA