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