Problem Statement

Given two sparse vectors, efficiently compute the dot product of them.

A sparse vector is one in which most elements are zero.

Implement class Solution:

• Solution(nums) Initializes the object with the vector nums
• dotProduct(vec) Calculates the dot product between the vec and instance of Solution.

Examples

• Example 1:

  • Input: vec1 = [1, 0, 0, 2], vec2 = [2, 3, 0, 1]
  • Expected Output: 4
  • Justification: The dot product is (1*2) + (0*3) + (0*0) + (2*1) = 2 + 0 + 0 + 2 = 4.

• Example 2:

  • Input: vec1 = [0, 0, 0, 0], vec2 = [1, 1, 1, 1]
  • Expected Output: 0
  • Justification: Since vec1 is all zeros, the dot product is 0 regardless of vec2's values.

• Example 3:

  • Input: vec1 = [1, 0, 0, 2, 3], vec2 = [0, 3, 0, 4, 0]
  • Expected Output: 8
  • Justification: The dot product is (1*0) + (0*3) + (0*0) + (2*4) + (3*0) = 8.

Constraints:

• n == nums1.length == nums2.length
• 1 <= n <= 10⁵
• 0 <= nums1[i], nums2[i] <= 100

Try it yourself

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