Axial-Tilted's blog

By Axial-Tilted, history, 7 months ago, In English

given a modular equation k = ax mod b where we know k and a and b find the smallest possible integer number for x

example (15 = 8x mod 25) , here the set of x that satisfy it up to the smallest integer are [1.875 , 3.75 , 5] but the smallest integer number is 5 how do i find the smallest integer number that satisfies the equation in o(1) or o(logb) anything thats not o(b) and above

searched alot and all i was able to find is the usage of EEX but i dont think its what iam looking for also modular inverse doesnt necessarily work since b (the mod) might not coprime with a or k

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7 months ago, # |
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First, for it to have solution, gcd(a,b) should be a factor of k. Then, you can find x and y and ax + by = gcd(a,b) (Bezout's identity) and gcd using euclid's algorithm. Then, multiply x by (k / gcd(a,b)