56 lines
1.5 KiB
Python
56 lines
1.5 KiB
Python
|
from collections import defaultdict
|
||
|
|
|
||
|
|
class Polynomial(object):
|
||
|
|
__slots__ = ["koefficients"]
|
||
|
|
|
||
|
|
def __init__(self, koefficients):
|
||
|
|
self.koefficients = list(koefficients)
|
||
|
|
# Remove trailing zeros.
|
||
|
|
while(self.koefficients and self.koefficients[-1] == 0):
|
||
|
|
self.koefficients.pop()
|
||
|
|
|
||
|
|
def __call__(self, x):
|
||
|
|
if(not isinstance(x, (float, int, complex))):
|
||
|
|
raise TypeError("unsupported type for {}: {}".format(x, type(x)))
|
||
|
|
|
||
|
|
result = 0
|
||
|
|
for i, a in enumerate(self.koefficients):
|
||
|
|
result += a * x**i
|
||
|
|
|
||
|
|
return result
|
||
|
|
|
||
|
|
def __add__(self, other):
|
||
|
|
if(not isinstance(other, Polynomial)):
|
||
|
|
raise TypeError("cannot add {} and {}".format(type(self), type(other)))
|
||
|
|
|
||
|
|
p1 = self.koefficients
|
||
|
|
p2 = other.koefficients
|
||
|
|
if(len(other.koefficients) > len(self.koefficients)):
|
||
|
|
p1, p2 = p2, p1
|
||
|
|
|
||
|
|
p2 += [0] * (len(p1) - len(p2))
|
||
|
|
|
||
|
|
return Polynomial([a + b for a,b in zip(p1, p2)])
|
||
|
|
|
||
|
|
def __mul__(self, other):
|
||
|
|
if(isinstance(other, (int, float, complex))):
|
||
|
|
return Polynomial([a * other for a in self.koefficients])
|
||
|
|
|
||
|
|
if(not isinstance(other, Polynomial)):
|
||
|
|
raise TypeError("cannot add {} and {}".format(type(self), type(other)))
|
||
|
|
|
||
|
|
result = defaultdict(int)
|
||
|
|
for i, k1 in enumerate(self.koefficients):
|
||
|
|
for j, k2 in enumerate(other.koefficients):
|
||
|
|
result[i + j] += k1 * k2
|
||
|
|
|
||
|
|
|
||
|
|
return Polynomial(result[i] for i in range(max(result)))
|
||
|
|
|
||
|
|
def __repr__(self):
|
||
|
|
return "{}({})".format(type(self).__name__, self.koefficients)
|
||
|
|
def __str__(self):
|
||
|
|
return " + ".join(["{}*x**{}".format(a, i) for i, a in enumerate(self.koefficients)])
|
||
|
|
|
||
|
|
|