comp.cpp: In function `int main()': comp.cpp:31: warning: `char c' might be used uninitialized in this function comp.cpp: In function `int num(char)': comp.cpp:15: warning: control reaches end of non-void function /tmp/ccboUr4h.o(.text+0xb5): In function `main': : the `gets' function is dangerous and should not be used.