Lintcode445 Cosine Similarity solution 题解

【题目描述】

Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the cosine of the angle between them. The cosine of 0° is 1, and it is less than 1 for any other angle.

See wiki: Cosine Similarity

Here is the formula:

Given two vectors A and B with the same size, calculate the cosine similarity.

Return 2.0000 if cosine similarity is invalid (for example A = [0] and B = [0]).

余弦相似度是度量一个内积空间的两个向量之间的相似度的度量，它测量了它们之间夹角的余弦值。0°的余弦是1,小于1其他角度。

看到维基:余弦相似性

这是公式:

给定两个向量A和B的大小相同，计算余弦相似度。

如果cos相似性无效(例如A =[0]和B =[0])，则返回2.0000。

【题目链接】

www.lintcode.com/en/problem/cosine-similarity/

【题目解析】

这是一道容易题。关键是通过循环分别求出分子和分母。

【参考答案】

www.jiuzhang.com/solutions/cosine-similarity/