Write a C++ program that asks the user to enter a string value in a variable named “Str”. The input string should be of size 20 characters (minimum). Next, apply following operation (in sequence) on the input string: 1) Find and print the length of the string. 2) Display string in reverse order. 3) Concatenate “Hello World” to the string. 4) Count number of words in updated string. 5) Convert whole string in lowercase.
Write a C++ code that computes the sum of the following series. Sum = 1! + 2! + 3! + 4! + …n! The program should accept the number from the user.