codeflash-internal/experiments/pie_test_set/p02634.py

16 lines
355 B
Python

def problem_p02634(input_data):
a, b, c, d = list(map(int, input_data.split()))
m = 998244353
D = [[0] * (d + 1) for _ in range(c + 1)]
D[a][b] = 1
for i in range(a, c + 1):
for j in range(b, d + 1):
D[i][j] += (D[i][j - 1] * i + D[i - 1][j] * j - D[i - 1][j - 1] * (i - 1) * (j - 1)) % m
return D[c][d]