Java Revision

This repository contains a collection of functions implemented in Java, focusing on string manipulation, numeric problem-solving and other basic programs. The repository includes the main classes: StringProblems, NumProb, BasicPrograms and Patterns. Each class is designed to perform a set of operations that can be useful in various programming contexts, for last minute java programming revision.

---

Classes Overview

StringProblems Class

The StringProblems class contains basic string manipulation methods, including:

• Reversing a String: Reverses the characters in a string.
• Palindrome Check: Verifies if a string is a palindrome.
• String Concatenation: Concatenates two strings together.
• Additional String Operations: Includes other string handling methods.

NumProb Class

The NumProb class provides solutions to various numeric problems, such as:

• Fibonacci Series Generation: Generates the Fibonacci sequence up to a specified term.
• Factorial Calculation: Computes the factorial of a given number.
• Prime Number Check: Checks if a number is prime.
• Palindrome Number Check: Verifies if a number is a palindrome.
• Greatest Common Divisor (GCD) and Least Common Multiple (LCM) calculation.
• Number Conversion: Converts numbers between binary, decimal, and octal formats.
• Area Calculation: Calculates the area of geometric shapes (circle, rectangle, etc.).
• Array Sorting: Implements sorting algorithms such as bubble sort, insertion sort, and merge sort.

BasicPrograms Class

The BasicPrograms class provides the following additional functionalities:

1. Binary Addition

   • Method: addBin(String bin1, String bin2)
   • Description: Adds two binary strings and returns the result as a binary string.

2. Prime Number Check

   • Method: isPrime(int n)
   • Description: Checks if a number n is prime.

3. Prime Series Generation

   • Method: primeSeries(int n)
   • Description: Generates an array of the first n prime numbers.

4. Fibonacci Number at Position

   • Method: fib(int num)
   • Description: Computes the Fibonacci number at a specified position num.

5. Fibonacci Series Generation

   • Method: fibSeries(int num)
   • Description: Generates an array containing the first num terms of the Fibonacci series.

6. Sum of Even Fibonacci Terms

   • Method: evenSumofFibSeries(int N)
   • Description: Computes the sum of Fibonacci numbers at even indices up to the 2 * N-th term.

7. Neon Number Check

   • Method: Neon(int num)
   • Description: Checks if a number is a neon number, where the sum of the digits of its square equals the number itself.

8. Vowel or Consonant Check

   • Method: VowelOrConsonant(char ch)
   • Description: Checks if a character is a vowel or consonant.

---

Patterns Class

The Patterns class provides functions to print various patterns of stars and numbers:

1. StarRightTriangle

   • Description: Prints a right-aligned triangle of stars.
   • Example:

     *
     * *
     * * *
     * * * *
     

2. StarLeftTriangle

   • Description: Prints a left-aligned triangle of stars.
   • Example:

           *
         * *
       * * *
     * * * *
     

3. NumPyramid

   • Description: Prints a pyramid of numbers incrementally from the top row down.
   • Example:

         1
       2 3 2
     3 4 5 4 3
     

4. RevPyramid

   • Description: Prints a reverse pyramid of stars.
   • Example:

     *******
      *****
       ***
        *
     

5. Pyramid

   • Description: Prints an upright pyramid of stars.

6. UpperStarTriangle

   • Description: Prints an upper triangle of stars.

7. SpiralMatrix

   • Description: Fills a square matrix with numbers in a spiral order.
   • Example (for n = 3):

     1 2 3
     8 9 4
     7 6 5
     

8. Diamond

   • Description: Prints a diamond shape with stars.

9. DownwardRightTriangle

   • Description: Prints a right triangle pointing downward.

10. DownwardPyramidMirror

    • Description: Prints a mirrored downward pyramid pattern.

11. PascalsTriangle

    • Description: Prints Pascal's triangle up to n rows.

12. HollowRectangle

    • Description: Prints a hollow rectangle with specified dimensions.

13. HollowSquare

    • Description: Prints a hollow square with stars around the edges.

Problems Class

- Problems solved using  

14. SquareWithDiagonals

    • Description: Prints a square pattern with diagonals filled in with stars.

15. FlippedRightTriangle

    • Description: Prints a right triangle with flipped alignment.

---

Problems Class

The Problems class contains implementations of various programming problems and exercises, leveraging Java's functionality to solve common algorithmic challenges. This class includes:

• Stream and Lambda Operations: Demonstrates the use of Java Streams API and lambda expressions for data processing.
• Collection Manipulations: Shows techniques for working with lists, maps, and sets.
• String Processing: Implements various string manipulation techniques using modern Java features.
• Functional Programming: Showcases functional programming concepts applied to solve common problems.
• Algorithmic Solutions: Includes implementations of algorithms like finding duplicates, palindromes, and prime numbers.

The class provides solutions to problems such as:

• Finding the first non-repeated character in a string
• Removing duplicates from collections
• Filtering elements based on conditions
• Sorting and grouping data
• Flattening nested collections
• Calculating statistical values (sum, average, min, max)
• Identifying palindromic strings
• Partitioning data into categories
• Processing infinite streams with limitations
• Extracting sublists from collections

These implementations demonstrate modern Java programming techniques and can serve as reference examples for solving similar problems in various applications.