/in/foo.cc: In function 'void check()':
/in/foo.cc:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<num.size(); i++) {
                   ~^~~~~~~~~~~
/in/foo.cc: In function 'void init(long long int)':
/in/foo.cc:33:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<num.size(); i++) {
                   ~^~~~~~~~~~~
/in/foo.cc:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<num.size(); i++) {
                   ~^~~~~~~~~~~
/in/foo.cc:74:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<num.size(); i++) {
                   ~^~~~~~~~~~~