/in/P4.cpp: In function 'int main()':
/in/P4.cpp:26:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < numbers.size(); i++) {
                     ~~^~~~~~~~~~~~~~~~
/in/P4.cpp:57:23: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = 0; i < result.size(); i++) {
                     ~~^~~~~~~~~~~~~~~
/in/P4.cpp:59:15: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         if (i < result.size() - 1) {
             ~~^~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors