I was wondering why multiplication of integers is O(n^2)? I’ve been taught addition and multiplication is considered 1 operation. Hence if I multiply an integer of n-digits with another integer of n-digits I should get O(n^2), which is true. But can someone explain it to me with an example.
Example
If I want to multiply 99 x 99. I can only count 3 operations
- 99 x 9
- 99 x 90
- 891 + 8910
Which would only give me O(3) when it should be O(4).