Compilare: user.cpp: In function ‘void filll(unsigned int, unsigned int, unsigned int)’: user.cpp:32:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(a[i][j]==k) ^ user.cpp: In function ‘int main()’: user.cpp:91:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i=1;i<=n;i++) ^ user.cpp:92:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int j=1;j<=m;j++) ^