18. Given the following piece of code, replicate the calculation of count [it's a sum of numbers] with a recursive function and write the equivalent piece of code. CODE: OUTPUT: #include sum(0) = 0 = 0 using namespace std; sum(1) = 0 + 1 = 1 const int BIG_N = 10; sum(2) = 0 + 1 + 2 = 3 int main() { sum(3) = 0 + 1 + 2 + 3 = 6 int count; sum(4) = 0 + 1 + 2 + 3 + 4 = 10 for(int i = 0; i ; using namespace std; const int BIG_N = 10; void recursive_sum (int x, int step) { string s = std::to_string(0); // for detailed sum information int r = 0; // for the result of a sum for ( -) { } if ( _) { } else { } } int main() { int depth = 0; recursive_sum(BIG_N, depth); return 0; } }