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from math import gcd as mathgcd
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from itertools import combinations
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from functools import wraps
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import random
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# home grown gcd
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def gcd(a, b):
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return a if b == 0 else gcd(b, a % b)
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def cooked(s: set[int]):
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for a, b in combinations(s, 2):
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if mathgcd(a, b) == 1:
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yield a, b
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printingTs = False
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def printTs(f):
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@wraps(f)
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def ff(*a, **kw):
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if printingTs:
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if a:
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print(*a)
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if kw:
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print(*kw.items())
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r = f(*a, *kw)
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if printingTs:
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print(r)
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return r
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return ff
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@printTs
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def smx(x, e, n, r=1): # this is not it cuh
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return (
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smx(inv(x, n), -e, n, r)
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if e < 0
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else r
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if e == 0
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else smx(x * x % n, e >> 1, n, r * x % n if e & 1 else r)
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)
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def realsmx(x, e, n):
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r = x
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for bro in map(int, bin(e)[3:]):
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r = (r * r) % n
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if bro:
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r = (r * x) % n
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return r
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@printTs
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def theREALsmx(x, e, n):
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"locked in"
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return (
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theREALsmx(inv(x, n), -e, n)
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if e < 0
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else x**e
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if e <= 1
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else theREALsmx(x, e >> 1, n) ** 2 % n
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if not e & 1
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else (x * theREALsmx(x, e & ~1, n)) % n
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)
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def realest(x=None, y=None, n=None):
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x = x or random.randint(-10e9, 10e9)
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y = y or random.randint(-10e9, 10e9)
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n = n or random.randint(2, 10e9)
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# print(x, y, n)
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if y < 0:
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try:
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p = pow(x, -1, n)
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except ValueError:
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p = None
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else:
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assert (p * x) % n == 1, f"{p = }, {(p*x)%n = }"
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try:
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i = inv(x, n)
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except ValueError:
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i = None
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else:
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assert (i * x) % n == 1, f"{i = }, {(i*x)%n = }"
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assert i == p, f"{i = }, {p = }"
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if gcd(x, n) != 1:
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return # not doing ts
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p = pow(x, y, n)
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s = smx(x, y, n)
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t = theREALsmx(x, y, n)
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assert p == s == t, f"{p = }, {s = }, {t = }"
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def xgcd(a, b) -> tuple[int, tuple[int, int]]:
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"answer at index 0, wiki ripoff"
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s, ps, r, pr = 0, 1, b, a
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# shit = 0
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while r != 0:
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# shit += 1
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# if shit > 1000:
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# raise RecursionError("SHIT")
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q = pr // r
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pr, r = r, (pr - q * r)
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ps, s = s, (ps - q * s)
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bt = 0 if b == 0 else (pr - ps * a) % b
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return (pr, (ps, bt))
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def inv(a, n):
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"also wiki ripoff"
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t, nt, r, nr = 0, 1, n, a % n
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# shit = 0
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while nr != 0:
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# shit += 1
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# if shit > 1000:
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# raise RecursionError("SHIT")
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q = r // nr
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r, nr = nr, (r - q * nr)
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t, nt = nt, (t - q * nt)
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# print(t, nt, r, nr)
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if r > 1:
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raise ValueError("base is not invertible for the given modulus")
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if t < 0:
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return t + n
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return t
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def fahhh(x, e, n):
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"only works for this specific thing"
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eb = f"{e:b}"
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print(f"x^H mod n = {x}^{e} mod {n}")
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print()
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print(f"H = {e}_10 = {eb}_2")
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print(
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",\n".join(reversed([f"h_{i} = {ie}_2" for i, ie in enumerate(reversed(eb))]))
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)
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r = x
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ee = 1
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print()
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print(f"x = x^{{{eb[0]}_2}}")
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print(f"h_{len(eb)-1} = {eb[0]}")
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print()
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print(f"r <- {x = }")
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print()
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for ie, i in zip(range(len(eb) - 2, -1, -1), eb[1:]):
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print(f"(x^{ee})^2 = x^{2*ee} = x^{{{2*ee:b}_2}}")
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print(f"SQ, h_{ie}")
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print()
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ee *= 2
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r *= r
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print(f"r <- r*r = {r}")
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print(f"r <- r mod n = {r%n}")
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r %= n
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print()
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if int(i):
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print(f"x^{ee}*x = x^{ee+1} = x^{{{ee+1:b}_2}}")
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print(f"MUL, h_{ie} = 1")
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print()
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ee += 1
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r *= x
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print(f"r <- r * x = {r}")
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print(f"r <- r mod n = {r%n}")
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r %= n
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else:
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print(f"h_{ie} = 0")
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print()
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print(f"x^H mod n = {x}^{e} mod {n} = {r}")
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return r
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if __name__ == "__main__":
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print("#1:", f"{gcd(52698, 61430) = }")
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E2 = {
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290345,
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218585,
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143231,
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164172,
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155768,
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423151,
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239707,
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153544,
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287390,
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480837,
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}
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print("#2:", *(f"gcd({m}, {n}) = {gcd(m,n)}" for m, n in cooked(E2)), sep="\n")
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print("#3:")
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fahhh(856, 25, 7)
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print(f"{pow(856, 25, 7) = }")
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print("#4:", f"{inv(65537, 35256) = }")
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