This assignment may be done in Java or in Lisp.

- Write a recursive function
`sumsq(int n)`that adds up the squares of the integers from`1`through`n`. - Giuseppe Peano (1858 - 1932) showed that all
arithmetic operations on natural numbers (nonnegative integers) could be
reduced to a single constant (0) and an operation
*successor*, which is available in Java as`++`(in Lisp,`1+`).Write a recursive function

`peanoplus(int x, int y)`, using only`++`and`--`, to perform addition according to the following definition:

peanoplus(x, y) = x, if y = 0; peanoplus(x + 1, y - 1), otherwise.Note that the

`++`and`--`operators must appear*before*the operands in the recursive call, so that the change will be made before the call; otherwise, the change will be made after the call, causing an infinite loop.We can think of

`peanoplus`as similar to an algorithm for adding together buckets of rocks: if the second bucket is empty, stop; otherwise move one rock from the second bucket to the first bucket and continue.Can you think of an

*invariant*(property that is always true) of`peanoplus`? What is the Big O of`peanoplus`? This function is naturally*tail-recursive*. - Write a function
`peanotimes(int x, int y)`that multiplies two integers using only`peanoplus`,`++`, and`--`, and is written in a recursive style similar to that of`peanoplus`. What is the Big O of`peanotimes`? - The mathematical notation ,
read
*n choose k*, is used to denote the number of distinct subsets of*k*items that can be chosen from a set of*n*distinct objects. It can be shown that:Although the

`factorial`function could be used in implementing*n*choose*k*, this would be inefficient for large values of*n*and small*k*. We have also seen that`factorial`quickly overflows the available accuracy of the basic types in Java.*n*choose*k*has the value*1*when*k = 0*. We can algebraically rewrite the definition into the following form for*k > 0*:Write a function

`choose(int n, int k)`, using a tail-recursive auxiliary function, to compute*n*choose*k*without using the`factorial`function. - Write functions
`sumlist(Cons lst)`to add up a list of`Integer`. Iterative versions`sumlist`and`sumlistb`are given. Write other versions of this function:`sumlistr`(recursive), and`sumlisttr`(tail-recursive using an auxiliary function). - Write a function
`sumsqdiff(Cons lsta, Cons lstb)`to sum squared item-by-item differences Σ(*x*)_{i}- y_{i}^{2}of two lists of`Integer`. Write several versions of this function: iterative, recursive, and tail-recursive using an auxiliary function. - Write a function
`maxlist(Cons lst)`to find the maximum value in a list of`Integer`. Write several versions of this function: iterative, recursive, and tail-recursive using an auxiliary function. - Binomial coefficients are the numeric factors of the products
in a power of a binomial such as (
*x + y*)^{n}. For example,*(x + y)*has the coefficients^{2}= x^{2}+ 2 x y + y^{2}`1 2 1`. Binomial coefficients can be calculated using Pascal's triangle:1 n = 0 1 1 1 2 1 1 3 3 1 1 4 6 4 1 n = 4

Each new level of the triangle has

`1`'s on the ends; the interior numbers are the sums of the two numbers above them. Write a program`binomial(int n)`to produce a list of binomial coefficients for the power`n`using the Pascal's triangle technique. For example,`binomial(2)`=`(1 2 1)`. You may write additional auxiliary functions as needed.`binomial`should be a recursive program that manipulates lists; it should not use`(choose n k)`. Use the function`(choose n k)`that you wrote earlier to calculate`(choose 4 k)`for`k`from`0`through`4`; what is the relationship between these values and the binomial coefficients?