Compilare: user.cpp: In function ‘void Check()’: user.cpp:168:13: warning: unused variable ‘x’ [-Wunused-variable] int x = 1; ^ user.cpp:165:9: warning: unused variable ‘st’ [-Wunused-variable] int st; ^ user.cpp: In function ‘void Scanf(int&)’: user.cpp:20:5: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] for(;'0'> buffer[pz] || buffer[pz] > '9'; bnext); ^ user.cpp:21:5: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] for(;'0'<=buffer[pz] && buffer[pz] <='9'; bnext) ^ user.cpp: In function ‘int main()’: user.cpp:184:35: 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:185:37: 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:134:9: warning: ‘pzbn’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i = ans.size() -1; i > pzbn; --i) ^