Compilare: user.cpp: In function ‘int check(int, int)’: user.cpp:12:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return e1>=1 && e1<=n && e2>=1 && e2<=m; ^ user.cpp:12:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return e1>=1 && e1<=n && e2>=1 && e2<=m; ^ user.cpp: In function ‘void det()’: user.cpp:57:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=I && ok;++i) ^ user.cpp: In function ‘void citire()’: user.cpp:72:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=I;++i){ ^