LintCode 余弦相似度题目分析代码

class Solution {
    /**
     * @param A: An integer array.
     * @param B: An integer array.
     * @return: Cosine similarity.
     */
    public double cosineSimilarity(int[] A, int[] B) {
        // write your code here
                int ab=0;
        if(sumArray(A) == 0 || sumArray(B) == 0)
        {
            return 2.00000;
        }
        for(int i=0;i<A.length;i++)
        {
            ab += A[i] * B[i];
        }
        return ab/Math.sqrt(sumArray(A))/Math.sqrt(sumArray(B));
    }
    
        public double sumArray(int[] A)
    {
        int sum = 0;
        for(int i=0;i<A.length;i++)
        {
            sum += A[i] * A[i];
        }
        return sum;
    }
}