## Description

07. Functions and recursion

7.01. Write a function which takes three numbers and returns

if the smallest one of them is prime.

7.02. Write a function which takes a character and returns if

the character is either digit or letter.

7.03. Write a function which takes four numbers – coordinates

of two points – , and returns the distance

between and .

7.04. Write a function which takes six numbers – coordinates

of three points in , and returns if they lie on a straight

line.

7.05. Write a function which takes three numbers –

coordinates of a vector, and returns the length of the

vector.

7.06. Write a function which by a given real number x and a

non-negative integer n returns x raised to the n-th power.

Use Karatsuba multiplication method (recursion).

7.07. Write a program which asks the user for a non-negative

integer and gives the number of Fibonacci.

7.08. Write a program which asks the user for a number and

prints the first numbers of Tribonacci.

7.09. Write a program which asks the user for a non-negative

integer and gives the n-th number of the sequence

, with .

7.10. Write a function which takes one integer and returns

.

7.11. Write a program which asks the user for the numbers

and prints the number of combinations . Hints:

, also and .

2D A(x1, y1) B(x2, y2)

A B

2D

3D

n n − th

n

n

n

an+2 = 5an+1 − 6an + 6n a0 = 0 a1 = 1

n

n!

0 ≤ k ≤ n (

n

k)

(

n

k) = n!

k!(n − k)! = Ck

n C0

n = Cn

n = 1 Ck

n = Ck

n−1 + Ck−1 n−1

7.12. Write a function which by given n, finds the number of

solutions of the system in natural numbers :

7.13. Write a function which takes two integers, which are

not all zero, and returns the largest positive integer that

divides each of the integers (greatest common divisor). For

example, the GCD of 8 and 12 is 4. Use [Euclid’s algorithm]

(https://en.wikipedia.org/wiki/Euclidean_algorithm “Markdown

Tutorial”).

7.14. Write a function which calculates the value of a given

polynomial using [Horner’s method](https://en.wikipedia.org/

wiki/Horner%27s_method “Markdown Tutorial”).

github.com/andy489

ℕ ∪ 0

x1 + x2 + x3 + X4 + x5 = n

x1 < 10

1 − ≤ x2 < 30

x4 20

x5 < 30

Example input Expected output

30 0

31 1

32 5

100 249000