Compilare: main.cpp: In function 'int main()': main.cpp:66:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<comp.size();i++) ~^~~~~~~~~~~~ main.cpp:71:35: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::vector<int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf(out,"%d\n",comp.size()); ^ main.cpp:73:37: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] fprintf(out,"%d ",vec.size()); ^ main.cpp:47:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&n,&m); ^ main.cpp:50:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&x,&y); ^