Compilare: user.cpp: In function 'int main()': user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp:5: warning: unused variable 'k' user.cpp:5: warning: 'y2' may be used uninitialized in this function user.cpp:5: warning: 'x2' may be used uninitialized in this function user.cpp:5: warning: 'y1' may be used uninitialized in this function user.cpp:5: warning: 'x1' may be used uninitialized in this function