Main.cc: In function ‘int main()’: Main.cc:6:5: warning: init-statement in selection statements only available with -std=c++1z or -std=gnu++1z if(n/100&&100/n;) ^ Main.cc:6:10: warning: statement has no effect [-Wunused-value] if(n/100&&100/n;) ~~~~~^~~~~~~ Main.cc:6:18: error: expected primary-expression before ‘)’ token if(n/100&&100/n;) ^ Main.cc:7:2: error: expected primary-expression before ‘else’ else if(n<=10&&n>=100) ^~~~