Compilare: user.cpp: In function ‘void dfs2(int)’: user.cpp:54:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( poz [nod] == lant [lantdenod[nod]].size() - 1 ) { ^ user.cpp:62:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( poz [nod] == lant [lantdenod[nod]].size() - 1 ) { ^ user.cpp: In function ‘int main()’: user.cpp:104:36: 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:105:38: 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:107:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m) ; ^ user.cpp:110:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x) ; ^ user.cpp:130:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y) ; ^