Compilare: main.cpp: In function 'int main()': main.cpp:5:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("roata.in","r",stdin); ^ main.cpp:6:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("roata.out","w",stdout); ^ main.cpp:49:13: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized] cout<<y-1; ^