/in/foo.cc: In function 'int main()':
/in/foo.cc:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < set; i++)
                    ^
/in/foo.cc:20:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0; j < n; j++)
                     ^
/in/foo.cc:22:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int m = 0; m < n; m++)
                      ^
/in/foo.cc:28:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0; j < n / 2 && flag; j++)
                     ^
/in/foo.cc:30:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int m = 0; m < n && flag; m++)
                      ^
/in/foo.cc:48:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < ans.size(); i++)
                    ^