/in/foo.cc: In function 'void Increment(point*, int)':
/in/foo.cc:55:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0; j < CH.size(); j++) {
                        ~~^~~~~~~~~~~
/in/foo.cc:60:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0; j < CH.size(); j++)
                        ~~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < CH.size(); i++) ans += area(P, CH[i]);
                    ~~^~~~~~~~~~~