smiley.cpp: In function `int Verifica(int&)': smiley.cpp:26: warning: NULL used in arithmetic smiley.cpp:36: warning: comparison between signed and unsigned integer expressions smiley.cpp:42: warning: comparison between signed and unsigned integer expressions smiley.cpp:48: warning: comparison between signed and unsigned integer expressions smiley.cpp:54: warning: comparison between signed and unsigned integer expressions smiley.cpp:60: warning: comparison between signed and unsigned integer expressions smiley.cpp:66: warning: comparison between signed and unsigned integer expressions smiley.cpp:72: warning: comparison between signed and unsigned integer expressions smiley.cpp:78: warning: comparison between signed and unsigned integer expressions smiley.cpp:84: warning: comparison between signed and unsigned integer expressions smiley.cpp:90: warning: control reaches end of non-void function smiley.cpp: In function `void Numarare()': smiley.cpp:92: warning: unused variable `int i'