ABC260 C - Changing Jewels

提出

code: python

n, x, y = list(map(int, input().split()))

# Rn * 1

# Rn => Rn-1 + Bn * X

# Bn => Rn-1 + Bn-1 * Y

# Rn => Rn-1 + (Rn-1 + Bn-1 * Y) * X => Rn-1 * (X + 1) + Bn-1 * (X * Y)

# 2 3 4

def exchange(level, rnum):

if level == 2:

return rnum * x * y

elif level == 1:

return 0

else:

return exchange(level - 1, x+1)

print(exchange(n, 1))

解答

code: python

n, x, y = list(map(int, input().split()))

# Rn => Rn-1 + Bn * X

# Bn => Rn-1 + Bn-1 * Y

def exchange(level, is_red):

if level == 1:

return 0 if is_red else 1

if is_red:

return exchange(level - 1, True) + exchange(level, False) * x

else:

return exchange(level - 1, True) + exchange(level - 1, False) * y

print(exchange(n, True))

メモ