Coding

Our 1st Program In Java- public class Main { public static void main(String[] args) { // Our 1st Program System.out.println("Hello World"); } Instagram 👇  For more Queries

Sorting Techniques 1. Selection Sort: Idea: The inner loop selects the minimum element in the unsorted array  and places the elements in increasing order. Time complexity: O(N 2 ) #include <iostream> using namespace std; int main() {     int n;     cin>>n;   int arr[n];    for(int i=0;i<n;i++){          cin>>arr[i];   }  for(int i=0;i<n-1;i++){       for(int j=i+1;j<n;j++){            if(arr[j]<arr[i]){                 int temp =arr[j];                  arr[j]=arr[i];             arr[i]=temp;           }           }      }for(int i=0;i<n;i++){       cout<<arr[i]<<" ";    }   return 0; } 2. Bubble Sort: Idea: ...

 OBJECT ORIENTED PROGRAMMING ● Object-Oriented Programming is a methodology or paradigm to design a  program using classes and objects. It simplifies the software development  and maintenance by providing some concepts defined below : ● Class is a user-defined data type which defines its properties and its  functions. Class is the only logical representation of the data. For  example, Human being is a class. The body parts of a human being are its  properties, and the actions performed by the body parts are known as  functions. The class does not occupy any memory space till the time an  object is instantiated. C++ Syntax (for class) : class student{ public: int id; // data member int mobile; string name; int add(int x, int y){ // member functions return x + y; } }; ● Object is a run-time entity. It is an instance of the class. An object can  represent a person, place or any other item. An object can operate on  both data members and ...

 Time and Space complexity                                  Time Complexity Time complexity of an algorithm quantifies the amount of time taken by an algorithm to run as a function of the length of the input. Types of notations 1. O-notation: It is used to denote asymptotic upper bound. For a given function g(n), we denote it by O(g(n)). Pronounced as “big-oh of g of n”. It also known as worst case time complexity as it denotes the upper bound in which algorithm terminates. 2. Ω-notation: It is used to denote asymptotic lower bound. For a given function g(n), we denote it by Ω(g(n)). Pronounced as “big-omega of g of n”. It also known as best case time complexity as it denotes the lower bound in which algorithm terminates. 3. !-notation: It is used to denote the average time of a program. Comparison of functions on the basis of time complexity It follows the following order in case of time complexit...

 Coding questions on functions Ques1. Write a program to print all prime numbers between 2 given numbers. #include<iostream> #include<math.h> using namespace std; bool isPrime(int num){ for(int i=2;i<=sqrt(num);i++){ if(num%i==0){ return false; } } return true; } int main(){ int a,b; cin>>a>>b; for(int i=a;i<=b;i++){ if(isPrime(i)){ cout<<i<<endl; } } return 0; } Ques2. Write a program to print Fibonacci sequence. #include<iostream> using namespace std; void fib(int n){ int t1=0; int t2=1; int nextTerm; for(int i=1;i<=n;i++){ cout<<t1<<endl; nextTerm=t1+t2; t1=t2; t2=nextTerm; } return; } int main(){ int n; cin>>n; fib(n); return 0; } Ques3. Write a program to find the factorial of a given number. #include<iostream> using namespace std; int fact(int n){ int factorial=1; for(int i=2;i<=n;i++){ factorial*=i; } return factorial; } int main(){ int n; cin>>n; int ans = fact(n); cout<<ans<<end...

 Functions A function is a block of code that performs a specific task. Why are functions used? 1.If some functionality is performed at multiple places in software, then rather than writing the same code, again and again, we create a function and call it everywhere. This helps reduce code redundancy. 2. Functions make maintenance of code easy as we have to change at one place if we make future changes to the functionality. 3.Functions make the code more readable and easy to understand. The syntax for function declaration is return- type function_name (parameter 1, parameter􀏮 …… parameter n){ //function_body } return-type The return type of a function is the data type of the variable that that function returns. For eg. if we write a function that adds 2 integers and returns their sum then the return type of this function will be ‘int’ as we will returning sum that is an integer value. When a function does not return any value, in that case the return type of the function is ‘void’....

How to check if a number is prime in C++  Prime Numbers Prime numbers are numbers which have only 2 distinct factors i.e 1 and the number itself. Eg. 2,3,5,7,19 etc. Ques1. Write a program to check if a number is prime or not. #include <iostream> #include<cmath> using namespace std; int main() { int n; cin>>n; bool flag=0; for(int i=2;i<=sqrt(n);i++){ if(n%i==0){ cout<<"Non-prime"<<endl; flag=1; break; } } if(flag==0){ cout<<"prime"<<endl; } return 0; } How to generate Armstrong numbers in C++ Armstrong Numbers Armstrong numbers are numbers which have their sum of cube of individual digits equal to the number itself. E.g 153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153. #include <iostream> #include<math.h> using namespace std; int main() { int n; cin>>n; int sum=0; int originaln=n; while(n>0){ int lastdigit= n%10; sum+= pow(lastdigit,3); n=n/10; } if(sum==originaln){ cout<<"Armstrong number"...

Operators in C++ Operators are nothing but symbols that tell the compiler to perform some  specific operations. Operators are of the following types - 1. Arithmetic Operators Arithmetic operators perform some arithmetic operation on one or two  operands. Operators that operate on one operand are called unary  arithmetic operators and operators that operate on two operands are  called binary arithmetic operators. +,-,*,/,% are binary operators. ++, -- are unary operators. Pre-incrementer : It increments the value of the operand instantly. Post-incrementer : It stores the current value of the operand temporarily  and only after that statement is completed, the value of the operand is  incremented. Pre-decrementer : It decrements the value of the operand instantly. Post-decrementer : It stores the current value of the operand temporarily  and only after that statement is completed, the value of the operand is  decremented. Example - int a=10; int b; ...

Switch Statement Switch case statements are a substitute for long if statements that compare a variable to multiple values. After a match is found, it executes the corresponding code of that value case. Syntax: switch (n) { case 1: // code to be executed if n == 1; break; case 2: // code to be executed if n == 2; break; default: // code to be executed if n doesn't match any of the above cases }   Key points : 1.The variable in switch should have a constant value. 2. The break statement is optional. It terminates the switch  statement and moves control to the next line after switch. 3. If break statement is not added, switch will not get terminated and  it will continue onto the next line after switch. 4. Every case value should be unique. 5. Default case is optional. But it is important as it is executed when  no case value could be matched. Examples: Ques1. Write a program to write a simple calculator. #include <iostream> using namespace std; int main() { int ...

 Jumps in Loops Jumps in loops are used to control the flow of loops. There are two statements used to implement jump in loops - Continue and Break. These statements are used when we need to change the flow of the loop when some specified condition is met. Ques1. Write a program to print all odd numbers till n. #include <iostream> using namespace std; int main() { int n; cout<<"Enter a number: "; cin>>n; for (int i=1; i<=n; i++) { if (i%2==0) { // i is even continue; } cout<<i<<endl; } return 0; } Ques2. Write a program to check if a given number is prime or not. #include <iostream> using namespace std; int main() { int n; cout<<"Enter a number: " cin>>n; int i; for (i=2; i<n; i++) { if (n%i==0) { //found a factor of n cout<<"Not a prime"<<endl; break; } } if (i==n) { //loop has completed all iterations cout<<"Prime Number"<<endl; } return 0; } Ques3. Write a program to...

Introduction   Jumps in loops are used to control the flow of loops. There are two statements used to implement jump in loops - Continue and Break. These statements are used when we need to change the flow of the loop when some specified condition is met. 1. Continue Continue statement is used to skip to the next iteration of that loop. This means that it stops one iteration of the loop. All the statements present after the continue statement in that loop are not executed. example : int i; for (i=1; i<=20; i++) { if (i%3==0) { continue; } cout<<i<<endl; } In this for loop, whenever i is a number divisible by 3, it will not be printed as the loop will skip to the next iteration due to the continue statement. Hence, all the numbers except those which are divisible by 3 will be printed. 2. Break Break statement is used to terminate the current loop. As soon as the break statement is encountered in a loop, all further iterations of the loop are stopped and control i...

Conditional statement (if-else)  In conditional control , the execution of statements depends upon the condition-test. If the condition evaluates to true, then a set of statements is executed otherwise another set of statements is followed. This control is also called Decision Control because it helps in making decision about which set of statements is to be executed.  If condition  The if statement is the most simple decision making statement in C++ programming. Using if statement we test some condition, if the condition is true then a block of statements is executed otherwise not. Let's take an example :- If(condition){  //body  } In the above syntax inside the brackets ( ) of if statement we will write our condition. If the condition is true then the statements written within the curly braces { } of if statement will execute otherwise not. We can write our condition using Arithmetic, Relational and Logical operators. Else-if Condition  When a piece of co...