Compilare: main.cpp: In member function 'i64 Polygon::area()': main.cpp:26:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < points.size() - 1 ; ++ i) { ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In member function 'i64 Polygon::edges()': main.cpp:36:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < points.size() - 1 ; ++ i) { ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:46:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &N) ; ^ main.cpp:48:41: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%lld %lld", &x, &y) ; ^ main.cpp:52:49: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%lld %lld", &x, &y) ; ^