백준-9184번(신나는 함수 실행)-python3

MAX = 21
dp = [[[0] * MAX for _ in range(MAX)] for __ in range(MAX)]


def w(a, b, c):
    if a <= 0 or b <= 0 or c <= 0:
        return 1
    if a > 20 or b > 20 or c > 20:
        return w(20, 20, 20)

    if dp[a][b][c]:
        return dp[a][b][c]

    if a < b < c:
        dp[a][b][c] = w(a, b, c - 1) + w(a, b - 1, c - 1) - w(a, b - 1, c)
        return dp[a][b][c]

    dp[a][b][c] = w(a - 1, b, c) + w(a - 1, b - 1, c) + w(a - 1, b, c - 1) - w(a - 1, b - 1, c - 1)
    return dp[a][b][c]


while True:

    a, b, c = map(int, input().split())

    if a == -1 and b == -1 and c == -1:
        break

    print("w(%d, %d, %d) = %d" % (a, b, c, w(a, b, c)))