diff --git a/1.py b/1.py
new file mode 100644
index 0000000..8eb2ebf
--- /dev/null
+++ b/1.py
@@ -0,0 +1,17 @@
+import numpy as np
+
+# 定义向量
+A = np.array([3, 4])
+B = np.array([1, 2])
+
+# 1. 计算A + B
+add_result = A + B
+print("A + B =", add_result)
+
+# 2. 计算2 × A
+mul_result = 2 * A
+print("2 × A =", mul_result)
+
+# 3. 计算A的长度（模）
+norm_A = np.linalg.norm(A)
+print("A的长度（模） =", norm_A)
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diff --git a/2.py b/2.py
new file mode 100644
index 0000000..b60072c
--- /dev/null
+++ b/2.py
@@ -0,0 +1,20 @@
+import numpy as np
+
+# 定义向量
+A = np.array([1, 2, 3])
+B = np.array([4, 5, 6])
+
+# 1. 计算点积A·B
+dot_product = np.dot(A, B)
+print("A·B =", dot_product)
+
+# 2. 计算余弦相似度
+cos_sim = np.dot(A, B) / (np.linalg.norm(A) * np.linalg.norm(B))
+print("余弦相似度 =", cos_sim)
+
+# 3. A = [1,0], B = [0,1]的余弦相似度
+A_new = np.array([1, 0])
+B_new = np.array([0, 1])
+cos_sim_new = np.dot(A_new, B_new) / (np.linalg.norm(A_new) * np.linalg.norm(B_new))
+print("A=[1,0], B=[0,1]的余弦相似度 =", cos_sim_new)
+print("原因：两个向量正交（点积为0），方向完全垂直，所以余弦相似度为0")
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diff --git a/260421-2509165004.py b/260421-2509165004.py
new file mode 100644
index 0000000..961f22d
--- /dev/null
+++ b/260421-2509165004.py
@@ -0,0 +1,4 @@
+s = "Hello"
+for c in s:
+    print(c, ord(c))
+    print(chr(65))  # 输出 A