mirror of
https://github.com/codeflash-ai/codeflash-internal.git
synced 2026-05-04 18:25:18 +00:00
23 lines
528 B
Python
23 lines
528 B
Python
def problem_p02878(input_data):
|
|
N, A, B = list(map(int, input_data.split()))
|
|
M = 998244353
|
|
P = N + 1
|
|
f = 1
|
|
F = [1] * P
|
|
I = [1] * P
|
|
z = 0
|
|
R = range
|
|
|
|
for n in R(1, P):
|
|
F[n] = f = f * n % M
|
|
|
|
I[N] = i = pow(f, M - 2, M)
|
|
|
|
for n in R(N, 1, -1):
|
|
I[n - 1] = i = i * n % M
|
|
|
|
for k in R(min(A + 1, N - B) if N - B - A else A + 1):
|
|
Q = N - B - k - 1
|
|
z = (z + (B - k) * F[B + k - 1] * I[B] * I[k] * F[Q + A - k] * I[Q] * I[A - k]) % M
|
|
|
|
return z if B else 1
|