Compilare: user.cpp: In function ‘void join_groups(int)’: user.cpp:16:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < enemy[node][i].size(); ++j) ^ user.cpp: In function ‘int main()’: user.cpp:34:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &t); ^ user.cpp:38:35: 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:40:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^ user.cpp:52:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^