Huge Multiplication

C++, Matlab. This was one of the assignments in the algorithm course I took before. Inputs are two big integers like 60 digits each. I implemented traditional multiplication method into my algorithm. Multiplication stage takes numbers in char format into a cell after each multiplication step. Then, it adds zeros to the end and front of numbers to make them inline before addition stage. Addition stage sums of digits in their vertical line one by one. Finally, it gives the result of product for two inputs as a char output since digit number of the product is too big.

Note: I checked if the inputs are valid or not in a very basic way. Character checking for char inputs could be added.

For example, two numbers (60 digits each):

‘415926535897932384626433832795028841971693993751058209749445’ and
‘182818284590452353602874713526624977572470936999595749669676’

The product (119 digits):

‘76038975808509199752257349866296465506516698245456284965108216281317973662575698005635922472140602306849234781474329820’

MATLAB version;