Compilare: main.cpp: In function 'int main()': main.cpp:19:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(frecv[i].size()==n-i){ ~~~~~~~~~~~~~~~^~~~~ main.cpp:20:44: 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\n",frecv[i].size()); ^ main.cpp:13:24: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ main.cpp:15:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&a); ^