完成作业3-2-1

2509165016-4.py

@@ -0,0 +1,19 @@
+import math
+
+def cosine_similarity(a, b):
+    dot = sum(x * y for x, y in zip(a, b))
+    norm_a = math.sqrt(sum(x**2 for x in a))
+    norm_b = math.sqrt(sum(x**2 for x in b))
+    return dot / (norm_a * norm_b)
+
+# 题目4-1,4-2
+A = [1, 2, 3]
+B = [4, 5, 6]
+dot_product = sum(a*b for a,b in zip(A,B))
+print("点积 =", dot_product)
+print("余弦相似度 =", cosine_similarity(A, B))
+
+# 题目4-3
+A2 = [1, 0]
+B2 = [0, 1]
+print("特殊向量余弦相似度 =", cosine_similarity(A2, B2))