Compilare: user.cpp: In function ‘void dfs2(int)’: user.cpp:62:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cnt == son[x].size()) ^ user.cpp: In function ‘int main()’: user.cpp:78:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("northrend.in", "r", stdin); ^ user.cpp:79:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("northrend.out", "w", stdout); ^ user.cpp:81:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:85:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^