Compilare: user.cpp: In function ‘bool VertexCover(int)’: user.cpp:20:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < Vector[nod].size(); i ++){ ^ user.cpp:31:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < Vector[nod].size(); i ++){ ^ user.cpp: In function ‘int main()’: user.cpp:46:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.in" ,"r", stdin ); ^ user.cpp:47:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.out","w", stdout); ^ user.cpp:49:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &N, &M, &K); ^ user.cpp:51:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &X, &Y); ^