E.E.A. .com
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Calculator

For the Euclidean Algorithm, Extended Euclidean Algorithm and multiplicative inverse.

Before you use this calculator

If you're used to a different notation, the output of the calculator might confuse you at first.
Even though this is basically the same as the notation you expect. If that happens, don't panic.
Just make sure to have a look the following pages first and then it will all make sense:

Euclidean Algorithm
For the basics and the table notation
Extended Euclidean Algorithm
Unless you only want to use this calculator for the basic Euclidean Algorithm.
Modular multiplicative inverse
in case you are interested in calculating the modular multiplicative inverse of a number modulo n
using the Extended Euclidean Algorithm

Input

Algorithm

Choose which algorithm you would like to use.

Numbers

Enter the input numbers:

Output

This is the output of the Extended Euclidean Algorithm using the numbers a=877 and b=940459:

a	b	q	r	s1	s2	s3	t1	t2	t3
877	940459	0	877	1	0	1	0	1	0
940459	877	1072	315	0	1	-1072	1	0	1
877	315	2	247	1	-1072	2145	0	1	-2
315	247	1	68	-1072	2145	-3217	1	-2	3
247	68	3	43	2145	-3217	11796	-2	3	-11
68	43	1	25	-3217	11796	-15013	3	-11	14
43	25	1	18	11796	-15013	26809	-11	14	-25
25	18	1	7	-15013	26809	-41822	14	-25	39
18	7	2	4	26809	-41822	110453	-25	39	-103
7	4	1	3	-41822	110453	-152275	39	-103	142
4	3	1	1	110453	-152275	262728	-103	142	-245
3	1	3	0	-152275	262728	-940459	142	-245	877

Answer

So we found that:

$gcd(877, 940459) = 1$
$s = 262728$
$t = -245$

Verification
If our answer is correct, then the absolute value of $s × a + t × b$ is equal to the $gcd$ of $a$ and $b$. We have:

$|s × a + t × b| = |262728 × 877 + -245 × 940459| = |230412456 + -230412455| = |1| = $ $1$
$gcd(a, b) = gcd(877, 940459) = $ $1$

As you can see, $| s × a + t × b| = gcd(a, b)$, so our calculation is correct!