結果

問題 No.1655 123 Swaps
ユーザー Kiri8128
提出日時 2021-06-25 02:26:56
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 398 ms / 2,000 ms
コード長 2,439 bytes
コンパイル時間 155 ms
コンパイル使用メモリ 82,304 KB
実行使用メモリ 135,808 KB
最終ジャッジ日時 2024-10-14 02:15:27
合計ジャッジ時間 9,743 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge2
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ファイルパターン 結果
sample AC * 3
other AC * 42
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

p, g, ig = 924844033, 5, 554906420
W = [pow(g, (p - 1) >> i, p) for i in range(24)]
iW = [pow(ig, (p - 1) >> i, p) for i in range(24)]
P = p
nn = 600600
fa = [1] * (nn+1)
fainv = [1] * (nn+1)
for i in range(nn):
    fa[i+1] = fa[i] * (i+1) % P
fainv[-1] = pow(fa[-1], P-2, P)
for i in range(nn)[::-1]:
    fainv[i] = fainv[i+1] * (i+1) % P
def convolve(a, b):
    def fft(f):
        for l in range(k, 0, -1):
            d = 1 << l - 1
            U = [1]
            for i in range(d):
                U.append(U[-1] * W[l] % p)
            for i in range(1 << k - l):
                for j in range(d):
                    s = i * 2 * d + j
                    t = s + d
                    f[s], f[t] = (f[s] + f[t]) % p, U[j] * (f[s] - f[t]) % p
    def ifft(f):
        for l in range(1, k + 1):
            d = 1 << l - 1
            U = [1]
            for i in range(d):
                U.append(U[-1] * iW[l] % p)
            for i in range(1 << k - l):
                for j in range(d):
                    s = i * 2 * d + j
                    t = s + d
                    f[s], f[t] = (f[s] + f[t] * U[j]) % p, (f[s] - f[t] * U[j]) % p
    n0 = len(a) + len(b) - 1
    if len(a) < 50 or len(b) < 50:
        ret = [0] * n0
        if len(a) > len(b): a, b = b, a
        for i, aa in enumerate(a):
            for j, bb in enumerate(b):
                ret[i+j] = (ret[i+j] + aa * bb) % p
        return ret
    
    k = (n0).bit_length()
    n = 1 << k
    a = a + [0] * (n - len(a))
    b = b + [0] * (n - len(b))
    fft(a), fft(b)
    for i in range(n):
        a[i] = a[i] * b[i] % p
    ifft(a)
    invn = pow(n, p - 2, p)
    for i in range(n0):
        a[i] = a[i] * invn % p
    del a[n0:]
    return a
def calc(a, b, c):
    M = a + b + c
    if M % 2: return 0
    M //= 2
    i3 = pow(3, P - 2, P)
    re = 0
    www = [1, 667811836, 257032196] # Cube root of 1 mod P
    A = [fainv[i] * fainv[a-i] % P * www[(2*i-a)%3] % P for i in range(a + 1)]
    B = [fainv[i] * fainv[b-i] % P * www[(b-2*i)%3] % P for i in range(b + 1)]
    AB = convolve(A, B)
    for i, x in enumerate(AB):
        if i > M: continue
        j = M - a - b + i
        if j < 0: continue
        re = (re + x * fainv[M-i] % P * fainv[j]) % P
    
    re = fa[M] ** 2 % P * re % P * 2 * i3 % P
    re = (re + fa[M*2] * fainv[a] * fainv[b] * fainv[c] * i3) % P
    return re
a, b, c = map(int, input().split())
print(calc(a, b, c))
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