splitwith regex to accelerate.
complex number can be represented as a string on the form “real+imaginaryi” where:
realis the real part and is an integer in the range [-100, 100].
imaginaryis the imaginary part and is an integer in the range [-100, 100].
- $i^2 == -1.$
Given two complex numbers
num2 as strings, return a string of the complex number that represents their multiplications.
Input: num1 = "1+1i", num2 = "1+1i"