Main.cc: In function ‘int main()’: Main.cc:5:11: warning: right operand of comma operator has no effect [-Wunused-value] cin>>a,b,c,d; ^ Main.cc:5:13: warning: right operand of comma operator has no effect [-Wunused-value] cin>>a,b,c,d; ^ Main.cc:5:14: warning: right operand of comma operator has no effect [-Wunused-value] cin>>a,b,c,d; ^ Main.cc:6:6: error: conflicting declaration ‘int e’ int e=sqrt((a-b)*(a-b)+(c-d)*(c-d)); ^ Main.cc:4:17: note: previous declaration as ‘double e’ double a,b,c,d,e; ^