Compilare: user.cpp: In function ‘void Check()’: user.cpp:126:13: warning: unused variable ‘x’ [-Wunused-variable] int x = 1; ^ user.cpp:123:9: warning: unused variable ‘st’ [-Wunused-variable] int st; ^ user.cpp: In function ‘void Read()’: user.cpp:34:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:38:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp: In function ‘int main()’: user.cpp:142:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("domino.in","r",stdin); ^ user.cpp:143:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("domino.out","w",stdout); ^ user.cpp: In function ‘void euler(int)’: user.cpp:97:9: warning: ‘pzbn’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i = ans.size() -1; i > pzbn; --i) ^