Compilare: user.cpp: In function ‘int main()’: user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cerere.in","r",stdin); ^ user.cpp:32:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cerere.out","w",stdout); ^ user.cpp:33:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:35:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &str[i]); ^ user.cpp:38:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^ user.cpp:45:13: warning: ‘rad’ may be used uninitialized in this function [-Wmaybe-uninitialized] Dfs(rad); ^