Compilare: user.cpp: In function ‘void unify(int, int)’: user.cpp:38:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘int main()’: user.cpp:56:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp:58:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^ user.cpp:61:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &bila[i].i, &bila[i].j); ^