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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=921 and b=347800:

a	b	q	r	s1	s2	s3	t1	t2	t3
921	347800	0	921	1	0	1	0	1	0
347800	921	377	583	0	1	-377	1	0	1
921	583	1	338	1	-377	378	0	1	-1
583	338	1	245	-377	378	-755	1	-1	2
338	245	1	93	378	-755	1133	-1	2	-3
245	93	2	59	-755	1133	-3021	2	-3	8
93	59	1	34	1133	-3021	4154	-3	8	-11
59	34	1	25	-3021	4154	-7175	8	-11	19
34	25	1	9	4154	-7175	11329	-11	19	-30
25	9	2	7	-7175	11329	-29833	19	-30	79
9	7	1	2	11329	-29833	41162	-30	79	-109
7	2	3	1	-29833	41162	-153319	79	-109	406
2	1	2	0	41162	-153319	347800	-109	406	-921

Answer

So we found that:

$gcd(921, 347800) = 1$
$s = -153319$
$t = 406$

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| = |-153319 × 921 + 406 × 347800| = |-141206799 + 141206800| = |1| = $ $1$
$gcd(a, b) = gcd(921, 347800) = $ $1$

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