CSE114: Homework 2 Spring 2022

CSE114: Introduction to Object Oriented Programming Spring 2022 Homework2: Due Date: Homework2 is due by 11:59 PM on Sunday, March 21, 2022. Submit your work (the .java source code files ONLY, not the compiled .class files!) through the “Homework2” link on Blackboard. You may submit an unlimited number of times; we will only grade the last/latest submission attempt, but be sure to attach all of your files to each submission attempt. Be sure to include your name and Stony Brook ID number in a comment at the beginning of each file that you submit. Submission Guidelines: 1. All the files should be inside a folder named as ‘LastName_FirstName_SBUID’ and upload it as zip file. [Example: A student named John Smith with SBUID 100200 will name the folder as Smith_John_100200 and should upload the zipped folder named Smith_John_100200.zip] 2. Each file should be named as HW*problem* (Example: ‘HW2problem1’) 3. If there are multiple classes for a problem, put each problem in a separate folder. Ensure that you compile the program before uploading (as structure mentioned above). If the program does not compile, you will lose points. Instructions: This assignment is worth 40 points (4*10). 1. Write a program that takes a user ID as an input from the keyboard and steps through every character, counting how many digits are in the ID; if there are exactly two digits, output that the user ID is valid, otherwise that it is invalid. [10 points] Here is a sample run: Enter the user ID: abc123de The input user ID is invalid Enter the user ID: xyz9a2bc The input user ID is valid 2. Write a program that inputs a word from the keyboard representing a binary number (0’s and 1’s). first your program should check that it is indeed a binary number, that is, the number contains only 0’s and 1’s. If that is not the case, your program should output that “The input number is not a valid binary number”. Otherwise, if that input word is a binary number and contains at least three consecutive 1’s, your program should out put that “The binary word is accepted”, otherwise that “The binary word is rejected”. [10 points] Here is a sample run: Enter the word: 12345 The input word is not a valid binary number Enter the word: 10101101 The binary word is rejected. Enter the word: 101011101 The binary word is accepted. 3. Write a method that checks whether the input string or a sentence (a string with spaces) is a palindrome or not. The method should be case insensitive and should ignore spaces. Write a test program that prompts the user to input a string and invokes this method. Some example runs are: [10 points] Enter the input string: madam Input string madam is a palindrome Enter the input string: banana Input string banana is NOT a palindrome Enter the input string: Race Car Input string Race Car is a palindrome Enter the input string: Too HOT to hoot Input string Too HOT to hoot is a palindrome 4. Two strings are anagrams if they are written using the same exact letters. Write a method to check if given two strings are anagrams or not. You have to ignore the case and space characters. Write a test program for that prompts the user to input two strings and invokes this method. Some example runs are: [10 points] Enter the first string: abbacba Enter the second string: abcabba abbacba and abcabba are anagrams Enter the first string: banana Enter the second string: cabana banana and cabana are NOT anagrams Enter the first string: Eleven plus two Enter the second string: Twelve plus one Eleven plus two and Twelve plus one are anagrams Part 1 import java.util.*; public class HW2problem1 { public static void main(String[] args){ Scanner input = new Scanner(System.in); System.out.print("Enter the user ID: "); String userID = input.nextLine(); int numOfDigits = 0; for (int i = 0; i < userID.length(); i++) { char character = userID.charAt(i); if (character >= '0' && character <= '9') numOfDigits++; } if (numOfDigits == 2) System.out.println("The input user ID is valid"); else System.out.println("The input user ID is invalid"); } } Part 2 import java.util.*; public class HW2problem2 { public static void main(String[] args){ Scanner input = new Scanner(System.in); System.out.print("Enter the word: "); String binary = input.nextLine(); String substring; int length = binary.length(); for (int i = 0; i < length; i++) { char character = binary.charAt(i); if (character != '0' && character != '1') { System.out.println("The input word is not a valid binary number"); System.exit(0); } if (character == '1' && i < length - 2) { int numOfOne = 1; substring = binary.substring(i + 1); for (int j = 0; j < 2; j++) { if (substring.charAt(j) == '1') numOfOne++; } if (numOfOne == 3) { System.out.println("The binary word is accepted."); System.exit(0); } } } System.out.println("The binary word is rejected."); } } Part 3 import java.util.*; public class HW2problem3 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter the input string: "); String userInput = input.nextLine(); String lowerCase = userInput.toLowerCase(); int length = userInput.length(); int i = 0; int j = length - 1; while (i < length) { char c1 = lowerCase.charAt(i); char c2 = lowerCase.charAt(j); if (c1 == ' ') { i++; continue; } if (c2 == ' ') { j--; continue; } if (c1 != c2) { System.out.printf("Input string %s is NOT a palindrome", userInput); System.exit(0); } i++; j--; } System.out.printf("Input string %s is a palindrome", userInput); } } Part 4 import java.util.*; public class HW2problem4 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter the first string: "); String string1 = input.nextLine(); System.out.print("Enter the second string: "); String string2 = input.nextLine(); String lowerCase1 = string1.toLowerCase(); String lowerCase2 = string2.toLowerCase(); for (int i = 0; i < lowerCase1.length(); i++) { char c = lowerCase1.charAt(i); if (c != ' ' && lowerCase2.indexOf(c) == -1) { System.out.printf("%s and %s are NOT anagrams", string1, string2); System.exit(0); } } for (int i = 0; i < lowerCase2.length(); i++) { char c = lowerCase2.charAt(i); if (c != ' ' && lowerCase1.indexOf(c) == -1) { System.out.printf("%s and %s are NOT anagrams", string1, string2); System.exit(0); } } System.out.printf("%s and %s are anagrams", string1, string2); } }