The KaratsubaOfman algorithm provides a striking example of how the Divide and Conquer technique can achieve an asymptotic speedup over an ancient algorithm. The classroom method of multiplying two n-digit integers requires ?(n 2 ) digit operations. Please convert the pseudocode into C++ source code. Also explain why this is the same as the pseudocode.

procedure karatsuba(num1, num2)
	if (num1 < 10) or (num2 < 10)
	return num1*num2
	/* calculates the size of the numbers */
	m = max(size_base10(num1), size_base10(num2))
	m2 = m/2
	/* split the digit sequences about the middle */
	high1, low1 = split_at(num1, m2)
	high2, low2 = split_at(num2, m2)
	/* 3 calls made to numbers approximately half the size */
	z0 = karatsuba(low1,low2)
	z1 = karatsuba((low1+high1),(low2+high2))
	z2 = karatsuba(high1,high2)

For example, ? m = max(size_base10(num1), size_base10(num2)) may not be valid in C++. How do you make it valid in C++?