yuh

There is no need for the break statement in your code, since the return statement exits the whole function (and thus exits the switch statement as well)

The "abs(mPos - cPos)" is a no-op since unsigned values likes size_t can't go negative.

omg göttlich

ever reached break here?

I don’t think we need to judge to divide by 0. When an incorrect parameter is entered, an error message should be displayed, prompting the inputter that the parameter is incorrect. Otherwise, people who use the function will think that 0 is also a valid divisor. Unless the requirements clearly indicate the need for compatibility with a divisor of 0. :)

Arent you looping over the field variable 3 times when you are finding each of c, m and d?

This type of metaprogramming is definitely more difficult than 4Kyu.

lack of divide by 0

no break; needed return breaks automatically

That regex will only work if you actually have two digits each. So something like 9:01:01 would fail.

push_back is O(1), but creating an nxn matrix will always be O(n^2).
And there's no point in e when you can write 1s directly to the matrix.

Is the push_back an O(n) operation? If it is then I guess this is still O(n^2).