Consider a set S of strings defined recursively as follows: ⚫ Base case: AES (A is the empty string, i.e. "" in programming.) Recursive rules: if x = S and yes then, 1. axbЄ S 2. xy Є S (a) List at least 8 distinct strings that are in S. You must use each recursive rule at least twice. (b) List at least 2 strings made up of only as and bs that are not in S.

Write a recursive function to print all the permutations of a string. For example, for the string abc, the printout is:abcacbbacbcacabcba(Hint: Define the following two functions. The second function is a helper function.def displayPermuation(s):def displayPermuationHelper(s1, s2): The first function simply invokes displayPermuation(" ", s). The secondfunction uses a loop to move a character from s2 to s1 and recursively invokes t with a new s1 and s2. The base case is that s2 is empty and prints s1 to the console.)Write a test program that prompts the user to enter a string and displays all its permutations.

Computer Science The language L = { | L(M) contains at least 4 strings that begin and end with 1 } IS an R.E. Non-Recursive language (trust me it IS ). What about the compliment of L? Is it RECURSIVE, R.E. Non-Recursive, or NON-R.E.?

2. Sum: a recursive function that computes the sum of integers 1, 2, 3, …., n for a given number n. So Sum(6) should return 1 + 2 + 3 + 4 + 5 + 6 , i.e. 21.sum(n) = n + sum(n-1)

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Pascal's triangle is a useful recursive definition that tells us the coefficients in the expansion of the polynomial (x + a)^n. Each element in the triangle has a coordinate, given by the row it is on and its position in the row (which you could call a column). Every number in Pascals triangle is defined as the sum of the item above it and the item above it and to the left. If there is a position that does not have an entry, we treat it as if we had a 0 there. *picture of the pascals triangle* Given the following recursive function signature, write the recursive function that takes a row and a column and finds the value at that position in the triangle. Assume that the triangle starts at row 0 and column 0. Examples: pascal(2, 1) -> 2,  pascal(1, 2) -> 0   public int pascal(int row, int column) {   }

PythonDesign a recursive function that accepts an integer argument, n, and prints the number 1 up through n.

8. Give a recursive definition of the sequence {an}, n =1, 2, 3, ... ifa) an = 4n − 2. b) an = 1 + (−1)n.c) an = n(n + 1). d) an = n2.

CodeW X b For func x C Solved X b Answer X https://codeworkou... CodeWorkout X270: Recursion Programming Exercise: Count Characters For function countChr() write the missing part of the recursive call. This function should return the number of times that the letter "A" appears in string "str". Recall that str.substring(a) will return the substring of str from position a to the end of str, while str.substring (a, b) will return the substring of str starting at position a and continuing to (but not including) the character at position b. Examples: countChr ("ctcoWCAt") -> 1 Your AnsSwer: 1 public int countChr(String str) { 2. if (str.length() return 0; } (0 4. { int count = 0; www. 5. 9. if (str.substring(0, 1).equals("A")) { count = 1 7. { 9. return count + > 1:10 AM 50°F Clear 12/4/2021 呼

Any problem that can be solved recursively can also be solved with a           .