Compilare: user.cpp: In function ‘int VertexCover(int)’: user.cpp:27:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < Vector[nod].size(); i ++){ ^ user.cpp:37:41: 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:68:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("canibali.in" ,"r", stdin ); ^ user.cpp:69:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("canibali.out","w", stdout); ^ user.cpp:71:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:73:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X[i]); ^ user.cpp:74:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Y[i]); ^ user.cpp:75:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Z[i]); ^ user.cpp:76:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T[i]); ^