Compilare: user.cpp: In function ‘void print(std::vector<int>&)’: user.cpp:12:29: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<int>::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n", v.size()); ^ user.cpp:14:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:44:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < brackets.size(); i++) ^ user.cpp:26:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("brackets.in", "r", stdin); ^ user.cpp:27:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("brackets.out", "w", stdout); ^ user.cpp:29:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &tests); ^