Dot Product of Two Sparse Vectors
给一个spare vector的类, 求dot product
class SparseVector {
int[] nums;
SparseVector(int[] nums) {
this.nums = nums;
}
// Return the dotProduct of two sparse vectors
public int dotProduct(SparseVector vec) {
int sum = 0;
for(int i = 0; i < nums.length; i++) {
sum += nums[i] * vec.nums[i];
}
return sum;
}
}
// Your SparseVector object will be instantiated and called as such:
// SparseVector v1 = new SparseVector(nums1);
// SparseVector v2 = new SparseVector(nums2);
// int ans = v1.dotProduct(v2);