Compilare: user.cpp: In function ‘void push(int)’: user.cpp:16:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < tab[h].size(); ++i) { ^ user.cpp: In function ‘void pop(int)’: user.cpp:29:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < tab[h].size(); ++i) { ^ user.cpp: In function ‘bool check(int)’: user.cpp:40:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < tab[h].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:55:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^ user.cpp:59:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &op, &num); ^