Compilare: user.cpp: In function ‘void afis()’: user.cpp:17:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=n; ++i) ^ user.cpp:19:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<=n; ++j) ^ user.cpp: In function ‘int main()’: user.cpp:48:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=n; ++i) ^ user.cpp:51:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<=n; ++j) ^ user.cpp:59:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=n; ++i) ^ user.cpp:60:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<=n; ++j) ^