Compilare: user.cpp: In function ‘int main()’: user.cpp:11:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=m;++i) ^ user.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;++i) ^ user.cpp:19:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;++i) ^ user.cpp:21:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=m;++j) ^ user.cpp:27:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<=n;++i) ^ user.cpp:29:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<=m;++j) ^ user.cpp:35:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;++i) ^ user.cpp:37:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=m;++j) ^