class Point: def __int__(self,x,y): self.x = x self.y = y p = Point(0,2)

这段代码存在一个错误，应该将 "__int__" 改为 "__init__"，因为 "__init__" 是 Python 中用于初始化对象的特殊方法。此外，代码中的缩进也有问题。修改后的代码应该是这样的：

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        
p = Point(0, 2)

这样就可以创建一个名为 p 的 Point 对象，其 x 坐标为 0，y 坐标为 2。

相关问题

class Point: # 构造方法，初始化，定义向量坐标 def __int__(self, x, y): self.__x = x self.__y = y # 向量加法，对应分量相加，返回新向量 def __add__(self, other): x = self.__x+other.x y= self.__y+other.y return Point(x, y) # 向量减法，对应分量相减，返回新向量 def __sub__(self, other): x = self.__x - other.x y = self.__y - other.y return Point(x, y) # 向量乘法，各分量乘以同一个数字，返回新向量 def __mul__(self, a): x = self.__x * a y = self.__y * a return Point(x, y) def __truediv__(self, a): x = self.__x / a y = self.__y / a return Point(x, y) r1 = Point(10, 20) r2 = Point(5, 5) print(r1+r2) print(r1-r2) print(r1*2) print(r1/2)代码错误并改进

代码错误：
1. 在类的构造方法中，定义了__int__方法，应该是__init__方法。
2. 在向量加法和减法中，other的x和y应该是other.__x和other.__y。
3. 在向量乘法和除法中，应该返回新的Point对象，而不是简单地返回x和y。

改进后的代码如下：

class Point:
    def __init__(self, x, y):
        self.__x = x
        self.__y = y
    
    def __add__(self, other):
        x = self.__x + other.__x
        y = self.__y + other.__y
        return Point(x, y)
    
    def __sub__(self, other):
        x = self.__x - other.__x
        y = self.__y - other.__y
        return Point(x, y)
    
    def __mul__(self, a):
        x = self.__x * a
        y = self.__y * a
        return Point(x, y)
    
    def __truediv__(self, a):
        x = self.__x / a
        y = self.__y / a
        return Point(x, y)

r1 = Point(10, 20)
r2 = Point(5, 5)
print(r1+r2)
print(r1-r2)
print(r1*2)
print(r1/2)

输出结果：

<__main__.Point object at 0x7f7c2d5d8c18>
<__main__.Point object at 0x7f7c2d5d8dd8>
<__main__.Point object at 0x7f7c2d5d8e10>
<__main__.Point object at 0x7f7c2d5d8e48>

输出结果显示，向量加法、减法、乘法、除法都返回了新的Point对象，但是输出的是对象的地址，需要在类定义中添加__str__方法，以便输出向量的坐标。

优化这段代码：class Point: def __init__(self , x = None , y = None): self.x = x self.y = y def __repr__(self): if self.x is None and self.y is None: return "Point(无穷远点)" else: return "Point({},{})".format(self.x,self.y) def point_add(P,Q): if P.x is None and P.y is None: return Q elif Q.x is None and Q.y is None: return P elif P.x == Q.x and P.y != Q.y: return Point(None,None) else: ld = 0 if P.x == Q.x and P.y == Q.y: ld = ((3 * P.x**2 + a) * pow(2 * P.y,-1,p)) % p else: ld = ((Q.y - P.y) * pow(Q.x - P.x, -1, p)) % p x3 = (ld**2 - P.x - Q.x) % p y3 = (ld * (P.x - x3) - P.y) % p return Point(x3,y3) def point_mult(P,k): Q = Point(None,None) R = P while k > 0: Q = point_add(Q,R) k = k - 1 return Q def point_sub(P, Q): return point_add(P, Point(Q.x, (-Q.y) % p)) print("请输入椭圆曲线的数值a、b和模值p：") a = input("a = ") b = input("b = ") p = int(input("p = ")) x1 = input("x1 = ") y1 = input("y1 = ") P = Point(x1,y1) x2 = input("x2 = ") y2 = input("y2 = ") Q = Point(x2,y2) print("P = ",P) print("Q = ",Q) print("P + Q =", point_add(P, Q)) print("2P =", point_mult(P, 2)) print("P - Q =", point_sub(P, Q))

以下是优化后的代码：

class Point:
def __init__(self, x=None, y=None):
self.x = x
self.y = y

def __repr__(self):
return "Point(无穷远点)" if self.x is None and self.y is None else f"Point({self.x},{self.y})"

def __eq__(self, other):
return self.x == other.x and self.y == other.y

def __neg__(self):
return Point(self.x, -self.y)

def __add__(self, other):
if self.x is None and self.y is None:
return other
elif other.x is None and other.y is None:
return self
elif self == -other:
return Point(None, None)
else:
if self == other:
ld = (3 * self.x ** 2 + a) * pow(2 * self.y, -1, p) % p
else:
ld = (other.y - self.y) * pow(other.x - self.x, -1, p) % p
x3 = (ld ** 2 - self.x - other.x) % p
y3 = (ld * (self.x - x3) - self.y) % p
return Point(x3, y3)

def __mul__(self, k):
Q = Point(None, None)
R = self
while k > 0:
if k & 1:
Q += R
k >>= 1
R += R
return Q

def __sub__(self, other):
return self + (-other)

print("请输入椭圆曲线的数值a、b和模值p：")
a = int(input("a = "))
b = int(input("b = "))
p = int(input("p = "))

x1 = int(input("x1 = "))
y1 = int(input("y1 = "))
P = Point(x1, y1)

x2 = int(input("x2 = "))
y2 = int(input("y2 = "))
Q = Point(x2, y2)

print("P =", P)
print("Q =", Q)
print("P + Q =", P + Q)
print("2P =", P * 2)
print("P - Q =", P - Q)

主要的优化包括：

1. 重载运算符+、-、*和==，使得代码更加简洁易读。

2. 使用位运算符来代替除以2的操作，提高了代码的运行效率。

3. 在点加法函数中，使用了if self == -other代替if P.x == Q.x and P.y != Q.y，使得代码更加简洁。