Compilare: user.cpp: In function 'int add_char(int, char)': user.cpp:22: warning: array subscript has type 'char' user.cpp:23: warning: array subscript has type 'char' user.cpp:24: warning: array subscript has type 'char' user.cpp:26: warning: array subscript has type 'char' user.cpp: In function 'int add_char2(int, char)': user.cpp:33: warning: array subscript has type 'char' user.cpp:34: warning: array subscript has type 'char' user.cpp:35: warning: array subscript has type 'char' user.cpp: In function 'int advance_char(int, char)': user.cpp:42: warning: array subscript has type 'char' user.cpp:43: warning: array subscript has type 'char' user.cpp:44: warning: array subscript has type 'char' user.cpp: In function 'int main()': user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp:75: warning: comparison between signed and unsigned integer expressions user.cpp:89: warning: comparison between signed and unsigned integer expressions user.cpp:91: warning: comparison between signed and unsigned integer expressions /tmp/cc6hLEjx.o: In function `main': user.cpp:(.text+0x14d): warning: the `gets' function is dangerous and should not be used.