This C++ function must be solved using stacks only (no recursion). "List stretch(string input, int k)" must be the header for this function and a helper function is ok to use. No need to make a main(). The logic is what's needed.

List stretch(string input, int k). A stretch of the input string is generated by repeating each character in order up to k times and at least once). For input string "abc" and k = 2, the output list should have: abc, aabe, abbe, abcc, aabbc, aabce, abbcc, aabbcc. (Again, the order does not matter.) List stretch(string input, int k). A stretch of the input string is generated by repeating each character in order up to k times and at least once). For input string "abc" and k = 2, the output list should have: abc, aabe, abbe, abcc, aabbc, aabce, abbcc, aabbcc. (Again, the order does not matter.)