Compilare: user.cpp: In function ‘int push_vector(std::vector<std::pair<int, int> >&, int)’: user.cpp:57:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < who.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:111:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < comp.size(); i++) ^ user.cpp:118:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 2; i < comp.size(); i++) ^ user.cpp:88:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta3.in","r",stdin); ^ user.cpp:89:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta3.out","w",stdout); ^ user.cpp:91:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &a, &b); ^ user.cpp:93:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &w); ^