Compilare: main.cpp: In function 'int main()': main.cpp:75:36: 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(fout,"%d\n",comp.size()); ^ main.cpp:76:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<comp.size();i++) ~^~~~~~~~~~~~ main.cpp:78:42: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] fprintf(fout,"%d ",comp[i].size()); ^ main.cpp:80:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<comp[i].size();j++) ~^~~~~~~~~~~~~~~ main.cpp: In function 'void read(int&)': main.cpp:26:38: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,dim,fin),poz=0; ^ main.cpp:31:42: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,dim,fin),poz=0; ^