Hello chegg expert please I need the problem description of each code just an introduction and explain the problem description. I am sick that why I couldn't do this homework please help me i need your help it's urgent and very important for me.

1. (Phone key pads) The international standard letterumber mapping found on the telephone is shown below: Write a program that prompts the user to enter a letter and displays its corresponding number. 2. (Display calendars) Write a program that prompts the user to enter the year and first day of the year and displays the calendar table for the year on the console. For example, if the user entered the year 2013, and 2 for Tuesday, January 1, 2013, your program should display 3. (Longest common prefix) Write a program that prompts the user to enter two strings and displays the largest common prefix of the two strings. Here are some sample runs: Enter the first string: Welcome to C++ - -etere Enter the second string: Welcome to programming The common prefix is welcome to 4. (Check password) Some websites impose certain rules for passwords. Write a method that checks whether a string is a valid password. Suppose the password rules are as follows: A password must have at least eight characters. A password consists of only letters and digits. A password must contain at least two digits. Write a program that prompts the user to enter a password and displays valid Password if the rules are followed or Invalid Password otherwise. 5. ( Eliminate duplicates) Write a method that returns a new array by eliminating the duplicate values in the array using the following method header: public static int[] eliminateDuplicates(int[] list) Write a test program that reads in ten integers, invokes the method, and displays the result. Here is the sample run of the program: 6. (Sorted?) Write the following method that returns true if the list is already sorted in increasing order. public static boolean isSorted(int[] list) Write a test program that prompts the user to enter a list and displays whether the list is sorted or not. Here is a sample run. Note that the first number in the input indicates the number of the elements in the list. This number is not part of the list