Compilare: user.cpp: In function 'void transform()': user.cpp:21: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'long int evaluate()': user.cpp:45: warning: comparison between signed and unsigned integer expressions /tmp/ccq5U2V5.o: In function `transform()': user.cpp:(.text+0x176): warning: the `gets' function is dangerous and should not be used.