Compilare: user.cpp: In function ‘int c2(short int)’: user.cpp:22:9: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] if(x==0|x==2||x==6||x==9) return 1; ^ user.cpp: In function ‘int main()’: user.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(a);i++) ^ user.cpp:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(a);i++) ^ user.cpp: In function ‘int c2(short int)’: user.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type] } ^