Compilare: user.cpp: In function ‘void ConstructSpareTable()’: user.cpp:35:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<Euler.size();i++) ^ user.cpp:38:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; (1<<j) <Euler.size(); j++) ^ user.cpp:39:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i + (1<<j) <= Euler.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:74:32: 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:75:34: 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:78:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:81:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:91:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^