The most efficient way to reverse a number

Question

I am looking for an efficient algorithm to reverse a number, e.g.

Input: 3456789

Output: 9876543

In C++ there are p

Answer 1

You may convert the number to string and then reverse the string with STL algorithms. Code below should work:

 long number = 123456789;
 stringstream ss;
 ss << number;
 string numberToStr = ss.str();

 std::reverse(numberToStr.begin(), numberToStr.end());

 cout << atol(numberToStr.c_str());

You may need to include those relevant header files. I am not sure whether it is the most efficient way, but STL algorithms are generally very efficient.