擅长:python、mysql、java
<p>这是一个可以运行的程序,不需要使用外部包。我定义了一个Poly类,它有两种方法:1)求值2)打印多项式。你知道吗</p>
<pre><code>class Poly():
def __init__(self, coeff):
self.coeff = coeff
self.N = len(coeff)
def evaluate(self, x):
res = 0.0
for i in range(self.N):
res += self.coeff[i] * (x**(self.N-i-1))
return res
def printPoly(self):
for i in range(self.N):
if i == self.N-1:
print("%f" % (abs(self.coeff[i])))
else:
if self.coeff[i] != 0.0:
print("%f * x**%d" % (abs(self.coeff[i]), self.N-i-1), end='')
if self.coeff[i+1] > 0:
print(" + ", end='')
else:
print(" - ", end='')
p = poly([1,-2,5]) # creating the polynomial object.
p.printPoly() # prints: 1.0 * x**2 - 2.0 * x**1 + 5
print(p.evaluate(0.0)) # prints: 5.0
</code></pre>