Good C++ solutions to the “Bring all the zeros to the back of the array” interview challenge

Question

I had an interview for a Jr. development job and he asked me to write a procedure that takes an array of ints and shoves the zeroes to the back. Here are the constraints (wh

Answer 1

This is O(n) so it may be what he's looking for:

auto arrBegin = begin(arr);
const auto arrEnd = end(arr);

for(int i = 0; arrBegin < arrEnd - i; ++arrBegin){
    if(*arrBegin == 0){
        i++;
        *arrBegin = *(arrEnd - i);
    }
}
std::fill(arrBegin, arrEnd, 0);