Correction_Java.java

//
//  JavaCorrection.java
//  JavaCorrection
//
//  Created by P1kachu on 07/02/15.
//  Copyright (c) 2015 P1kachu. All rights reserved.
//
//  Reviewed by:
//      - Thommath
//      - PraveenKishore
//      - (null)
//

import java.util.Scanner; // For user input
import java.util.Random;
class JavaCorrection
{
        public static void main(String args[])
        {

                // Part One:


                // FIXME: Declare variables
                // Declare two variables: an integer named "age", and a string named "name" with corresponding values (your name and age)
                int age = 20;
                String name = "Darth Vader";

                // FIXME: Print
                // Print the following sentence in the console "You are NAME and you are AGE years old !". Don't forget to add a newline at the end if required
                System.out.println("You are " + name + " and you are " + age + " years old !");

                // FiXME: Concatenation
                // Create a new string variable called "hello" which value is "Hello ". Add "name" at the end of "hello" (Concatenation) then print it
                String hello = "Hello ";
                hello += name;
                System.out.println(hello);

                // FIXME: Array
                // create a new string array called "shoppingList", with three elements of your choice. Create an int variable containing the number of
                // elements in "shoppingList" (using a function of the array/using the array)
                String[] shoppingList = { "Tea","Raspberry","Pi" };
                int nbOfElts = shoppingList.length;

                // FIXME: For-loop - Integer
                // Create a simple for-loop for an integer "i" going from 1 to 10 that prints the value of "i"
                for (int i = 1; i < 11; i++){
                        System.out.println(i);
                }

                // FIXME: For-loop - shoppingList
                // Create a for loop that iterate through "shoppingList" and prints each element.
                for (int i = 0; i < nbOfElts; i++){
                        System.out.println(shoppingList[i]);
                }

                // FIXME: Foreach-loop
                // Do the same with a foreach-loop.
                for (String item : shoppingList){
                        System.out.println(item);
                }

                // FIXME: If-statement
                // Modify the first for-loop (with i from 1 to 10) such that it prints "(value of i) is even" when "i" is divisible
                // by 2 (You may want to learn more about "modulo" (%)). Else, print "(value of i) is odd".
                for (int i = 1; i < 11; i++){
                        if(i % 2 == 0){
                                System.out.println(i + " is even");
                        } else {
                                System.out.println(i + " is odd");
                        }
                }
                // FIXME: Sum Up
                // Create a string variable called "element" with the value of your choice. Then create a for-loop that checks if "shoppingList" contains
                // "element". If yes, print "You have to buy (value of element) !", and stop the loop (search how to stop a loop).
                // If not, print "Nope, you don't need (value of "element")".
                String element = "Pi";
                int tmp = 0;
                for (int i = 0; i < nbOfElts; i++){
                        if (shoppingList[i].equals(element)){
                                tmp = 1;
                        }
                }
                if (tmp == 1){
                        System.out.println("You have to buy " + element + " !");
                } else {
                        System.out.println("Nope, you don't need " + element);
                }

                // Part Two:


                // FIXME: Functions - Ascii
                // Create a function that returns nothing and which doesn't takes any parameter. It should just be named "TriForce"
                // and print the TriForce symbol (one triangle over two other ones, can be found on internet) with "TRIFORCE"
                // Don't forget to call the function !
                triForce();

                // FIXME: Functions - One parameter
                // Create a function that takes a string as parameter and returns "Hello (value of string) !"
                System.out.println(hello("Luke"));

                // FIXME: Functions - Multiple parameters
                // Create a function that takes two integers as parameters and returns the addition of these two.
                // You can do the same with multiplication, subtraction and division.
                System.out.println(addition(18,24));
                System.out.println(division(336,8));
                System.out.println(multiplication(21,2));
                System.out.println(subtraction(44,2));

                // FIXME: User input
                // Create a string variable that takes what the user enters in the console as value. Then print "You entered (value of string)"
                Scanner user_input = new Scanner(System.in);
                String user_inputS = user_input.next();
                System.out.println("You entered " + user_inputS);

                // FIXME: While loop
                // Create a while loop that takes a number and divides it by 2 until it is less than 3
                int nb= 100;
                while(nb >= 3){
                        System.out.println(nb);
                        nb /= 2;
                }

                // FIXME: do-While loop
                // Do the same with a do-while loop
                nb = 100;
                do{
                        System.out.println(nb);
                        nb /= 2;
                }while(nb >= 3);

                // FIXME: Random generator
                // Create a function that returns a random number
                randInt();

                // FIXME: Random generator with bounds
                // Create another function that returns a random number between two bounds given as parameters.
                randIntBounds(0,5);

                // FIXME: Multidimensional array
                // Create a two dimensional int array of 3 columns and 3 rows. Use 2 for-loops to add a random number
                // between 1 and 9 in each of the 9 rooms.
                // You may use one of the two previously created function.
                // Then print them such that they appear like this (with [x1,x9] being the 9 random integers):
                // {x1,x2,x3,}
                // {x4,x5,x6,}
                // {x7,x8,x9,}
                int size = 3;
                int[][] array = new int[size][size];
                for (int i = 0; i < size; i++){
                        for (int j = 0; j < size; j++){
                                array[i][j] = randIntBounds(0,9);
                        }
                }

                for (int i = 0; i < size; i++){
                        System.out.print("{");
                        for (int j = 0; j < size; j++){
                                System.out.print(array[i][j] + ",");
                        }
                        System.out.println("}");
                }

                // FIXME: Switch
                // Create a Switch that takes an integer "a" and return a sentence regarding the value of a
                // (Create 3 statements for 3 specific values and a default one)
                int a = Integer.parseInt(user_input.next());

                switch(a){
                        case 1:
                                System.out.println("a = 1");
                                break;
                        case 2:
                                System.out.println("a = 2");
                                break;
                        case 3:
                                System.out.println("a = 3");
                                break;
                        default:
                                System.out.println("a != 1/2/3\n");
                                break;
                }

                // FIXME: logic Gates
                // Create 7 functions for each logic gates (And, Or, No, Nand, Nor, Xnor, Xor).
                // Each function takes two booleaneans as parameters and returns the result of the logic gate.
                // (or You can do it with a switch and only one function)
                System.out.println(logicGate("true",0,"false"));

                // FIXME - Reverse
                // Create a function that reverse a string
                System.out.println(reverseString("Hello!"));

                System.out.println("");

                // Part: ADVANCED
                // Following code is for Advanced Exercise
                // Microsoft Interview Question
                System.out.println(reverseWordOrder("This is a Cat"));
                System.out.println("");

                // Facebook Interview Question 1
                if(isPalindrome("Malayalam")) {
                        System.out.println("Palindrome");
                } else {
                        System.out.println("Not a palindrome");
                }
                System.out.println("");

                // Facebook Interview Question 2
                if(facebook2(new int[] { 1, 12, 11, 3, 4})) {	// Returns true if 2 or more numbers is 12
                        System.out.println("Two or more numbers is 12");
                } else {
                        System.out.println("Two or more numbers is not 12");
                }
                System.out.println("");

                // Microsoft Interview Question
                int b[][] = new int[][]{{  1,  2,  3,  4 },
                        {  5,  6,  7,  8 },
                        {  9, 10,  0, 11 },
                        { 12, 13, 14, 15 }};
                replaceWith0(b);
                System.out.println("");

                // HackerRank Data Structure & Algorithm Questions
                // You are given an array of integers of size N . You need to print
                // the sum of the elements of the array.
                int sum = 0;
                int num[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
                for(int i = 0; i < num.length; i++) {
                        sum += num[i];
                }
                System.out.println("Sum: " + sum);
                System.out.println("");

                // HackerRank Data Structure & Algorithm Questions:
                // Your teacher has given you the task to draw the structure of a staircase.
                // Being an expert programmer, you decided to make a program for the same.
                // You are given the height of the staircase. You need to print a
                // staircase as shown in the example.
                // Output:
                //      #
                //     ##
                //    ###
                //   ####
                //  #####
                // ######
                int height = 6;
                int s = height-1, h = 1;	// s: For storing number of space to be printed next, h for storing number of '#' to be printed next
                for(int i = 0; i < height; i++) {
                        for(int j = 0; j < s; j++) {
                                System.out.print(" ");
                        }
                        for(int k = 0; k < h; k++) {
                                System.out.print("#");
                        }
                        s--;
                        h++;
                        System.out.println("");
                }

        }

        //Functions Declarations

        static void triForce(){
                System.out.println("   /\\  ");
                System.out.println("  /__\\ ");
                System.out.println(" /\\  /\\  ");
                System.out.println("/__\\/__\\ ");
                System.out.println("TRIFORCE");
        }

        static String hello(String name){
                return "Hello " + name + " !\n";
        }
        static int addition(int a, int b){
                return a + b;
        }

        static int subtraction(int a, int b){
                return a - b;
        }

        static int multiplication(int a, int b){
                return a * b;
        }

        static int division(int a, int b){
                return a / b;
        }


        public static int randInt(){
                Random rand = new Random();
                int randomNum = rand.nextInt(Integer.MAX_VALUE);
                return randomNum;
        }

        public static int randIntBounds(int min, int max){
                Random rand = new Random();
                int randomNum = rand.nextInt((max - min) + 1) + min;
                return randomNum;
        }

        static boolean logicGate(String left, int door, String right){
                boolean a;
                boolean b;

                if (left.equals("true"))
                        a = true;
                else a = false;

                if (right.equals("true"))
                        b = true;
                else b = false;


                switch (door){
                        case 0:
                                return and(a, b);
                        case 1:
                                return or(a, b);
                        case 2:
                                return no(a);
                        case 3:
                                return nand(a, b);
                        case 4:
                                return nor(a, b);
                        case 5:
                                return xor(a, b);
                        case 6:
                                return xnor(a, b);
                        default:
                                return false;
                }
        }

        static boolean and(boolean a, boolean b){
                if (a && b)
                        return true;
                else
                        return false;
                // return (a && b)
        }


        static boolean or(boolean a, boolean b){
                if (a || b)
                        return true;
                else
                        return false;
                // return (a || b)
        }


        static boolean no(boolean a){
                if (a)
                        return false;
                else
                        return true;
                // return (!a)
        }


        static boolean nand(boolean a, boolean b){
                if (a && b)
                        return false;
                else
                        return true;
                // return !(a && b)
        }


        static boolean nor(boolean a, boolean b){
                if (a && b)
                        return true;
                else
                        return false;
                // return !(a || b)
        }

        static boolean xor(boolean a, boolean b){
                if ((a && b) || (a && b))
                        return true;
                else
                        return false;
                // return ((a && b) || (a && b))
        }

        static boolean xnor(boolean a, boolean b){
                if ((a && b) || (a && b))
                        return false;
                else
                        return true;
                // return !((a && b) || (a && b))
        }

        static String reverseString(String str){
                char[] array = str.toCharArray();
                String stringy = "";
                for (int i = str.length() - 1; i >= 0; i--)
                        stringy += array[i];
                return stringy;
        }

        static String reverseWordOrder(String input) {
                /** Microsoft Interview Question:
                 * Write a Function to Reverse the word order of String
                 * Sample: "This is a Cat" -> "Cat a is This"
                 **/
                String output = "";
                String words[] = input.split(" ");	// Split the sentence into words
                for(int i = words.length - 1; i >= 0; i--) {
                        output = output + words[i] + " ";
                }
                return output;
        }

        static boolean isPalindrome(String input) {
                /** Facebook Interview Question:
                 * Write a Function which proves if a String is a Palindrome
                 * Note: Word which is read the same Backward as Forward
                 **/
                String reverse = new StringBuilder(input).reverse().toString();
                if(reverse.equalsIgnoreCase(input)) {
                        return true;
                } else {
                        return false;
                }
        }

        static boolean facebook2(int a[]) {
                /** Facebook Interview Question:
                 * Given a List of Arrays, write a Function which will
                 * Return True if Two of the Number equal 12
                 */
                int count  = 0;
                for(int i = 0; i < a.length; i++) {
                        if(a[i] == 12) {
                                count++;
                        }
                        if(count >= 2) {
                                return true;
                        }
                }
                return false;
        }

        static int[][] replaceWith0(int a[][]) {
                /** Microsoft Interview Question:
                 * With a given Array  (Multidimensional Array) find location
                 * Zero & Replaces all Columns & Rows with Zero
                 * Sample:
                 * Input:{  1,  2,  3,  4 }
                 *		{  5,  6,  7,  8 }
                 *		{  9, 10,  0, 11 }
                 *		{ 12, 13, 14, 15 }
                 *
                 * Output: {  1,  2,  0,  4 }
                 *		{  5,  6,  0,  8 }
                 *		{  0,  0,  0,  0 }
                 *		{ 12, 13,  0, 15 }
                 **/

                int m = -1, n = -1;
                // Find the row and column index of 0
                for(int i = 0; i < a.length; i++) {
                        for(int j = 0; j < a[0].length; j++) {
                                if(a[i][j] == 0) {
                                        m = i;
                                        n = j;
                                        break;
                                }
                        }
                }

                // Replace rows and and columns of that index with 0
                if(m != -1 && n != -1) {
                        for(int i = 0; i < a.length; i++) {
                                for(int j = 0; j < a[0].length; j++) {
                                        if(i == m) {
                                                a[i][j] = 0;
                                        }
                                        if(j == n) {
                                                a[i][j] = 0;
                                        }
                                }
                        }
                }

                // Print the matrix
                System.out.println("Output: ");
                for(int i = 0; i < a.length; i++) {
                        for(int j = 0; j < a[0].length; j++) {
                                System.out.print(a[i][j] + "\t");
                        }
                        System.out.println("");
                }
                return a;
        }
}