# 题目1
s = "Hello"
# 1. 用 ord() 函数打印每个字符的 ASCII 码
print("1. 'Hello' 每个字符的 ASCII 码：")
for char in s:
    ascii_code = ord(char)
    print(f"字符 '{char}' 的 ASCII 码：{ascii_code}")

# 2. 用 chr() 函数验证：字符65对应的是大写字母A
print("\n2. 验证 chr() 函数：")
char_from_code = chr(65)
print(f"ASCII 码 65 对应的字符是：'{char_from_code}'")
# 题目2：
# 题目3
import math

print("===== 题目3 计算 =====")
A = [3, 4]
B = [1, 2]
add_result = [a + b for a, b in zip(A, B)]
print("A + B =", add_result)

# 2. 数乘 2*A
mul_result = [2 * x for x in A]
print("2 * A =", mul_result)

# 3. 向量 A 的模长
norm_A = math.sqrt(A[0]**2 + A[1]**2)
print("A 的模长 =", norm_A)
# 题目4
print("\n===== 题目4 计算 =====")
A4 = [1, 2, 3]
B4 = [4, 5, 6]

dot_product = sum(a * b for a, b in zip(A4, B4))
print("A · B =", dot_product)

norm_A4 = math.sqrt(sum(x**2 for x in A4))
norm_B4 = math.sqrt(sum(x**2 for x in B4))

cos_sim = dot_product / (norm_A4 * norm_B4)
print("A 的模长 =", round(norm_A4, 4))
print("B 的模长 =", round(norm_B4, 4))
print("余弦相似度 =", round(cos_sim, 4))

print("\n===== 特殊向量余弦相似度 =====")
A0 = [1, 0]
B0 = [0, 1]
dot0 = A0[0] * B0[0] + A0[1] * B0[1]
norm0_A = math.sqrt(A0[0]**2 + A0[1]**2)
norm0_B = math.sqrt(B0[0]**2 + B0[1]**2)
cos0 = dot0 / (norm0_A * norm0_B)
print("A=[1,0], B=[0,1] 余弦相似度 =", cos0)