C++ Integer Digit Permutations. Coded this up when I thought I was working with permutable primes rather than circular primes. Thought I'd salvage my time and share it for anyone looking for something similar in the future.

gistfile1.txt

vector<int> digitPermutationsOf(int n) {
  vector<int> permutations;

  // Convert integer to char array of digits
  char digits[16]; // Max 16 digits allowed for ints
  int size = sprintf(digits, "%d", n);

  // Iterate through the digit array and save each permutation
  std::sort(digits, digits + size);
  do {
    permutations.push_back(atoi(digits));
  } while (std::next_permutation(digits, digits + size));

  // Return all permutations of n
  return permutations;
}