Compilare: user.cpp: In function ‘int main()’: user.cpp:56:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < g[group[i]].size(); j++) ^ user.cpp:26:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ user.cpp:35:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &x); ^