What are two ways to launch a cryptanalytic attack against a cipher (based upon what the attacker knows or has in possession)? be sure to provide detailed examples.

Print "usernum1 is negative." if usernum1 is less than 0. end with newline. convert usernum2 to 0 if usernum2 is greater than 10. otherwise, print "usernum2 is less than or equal to 10.". end with newline

When is it appropriate to use an absolute reference

Write a program that prompts the user to input a string. the program then uses the function substr to remove all the vowels from the string. for example, if str = "there", then after removing all the vowels, str = "thr". after removing all the vowels, output the string. your program must contain a function to remove all the vowels and a function to determine whether a character is a vowel.