Compilare: user.cpp: In function ‘void filll(coord)’: user.cpp:32:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] ++f[mat[x.l][x.c]]; ^ user.cpp: In function ‘int main()’: user.cpp:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ferma3.in","r",stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ferma3.out","w",stdout); ^ user.cpp:86:14: warning: ‘cod’ may be used uninitialized in this function [-Wmaybe-uninitialized] char cod; ^