Greatest common divisor of four P57852

Statement

thehtml

Write a function that computes the greatest common divisor of four natural numbers a, b, c and d using the fast version of the Euclidean algorithm.

Interface

C++,C	int gcd4(int a, int b, int c, int d);
Java	public static int gcd4(int a, int b, int c, int d);
Python	gcd4(a, b, c, d) # returns int
	gcd4(a: int, b: int, c: int, d: int) -> int

Precondition

The four numbers are strictly greater than zero.

Observation You only need to submit the required procedure; your main program will be ignored.

Hint

Using the function gcd(a, b) of the exercise ‍ should be useful.

Public test cases

Input/Output

gcd4(66, 12, 1200, 36) → 6
gcd4(10, 6, 21, 35) → 1

Information