Compilare: user.cpp: In member function ‘void GRAPH::dfs(int, int)’: user.cpp:42:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<a[nod].size(); i++) ^ user.cpp: In member function ‘void GRAPH::rmq()’: user.cpp:51:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<Euler.size(); i++) ^ user.cpp:53:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; (1<<i)<Euler.size(); i++) ^ user.cpp:54:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<Euler.size()-(1<<i); j++) ^ user.cpp: In function ‘int main()’: user.cpp:75:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in", "r", stdin); ^ user.cpp:76:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lca.out", "w", stdout); ^ user.cpp:80:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:85:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:93:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^