Compilare: main.cpp: In function 'void verif_permutation(long long int*)': main.cpp:112:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < c_var.size(); i++) ~~^~~~~~~~~~~~~~ main.cpp:113:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < l_var.size(); j++) { ~~^~~~~~~~~~~~~~ main.cpp: In member function 'void instream::advance()': main.cpp:43:44: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input_file); ^ main.cpp: In constructor 'instream::instream(const char*)': main.cpp:16:40: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input_file); ^