谁能给我一点提示？

#include <iostream>
#include <cmath>
using namespace std;
int main(){
	double a,b;
	char ch;
	cin>>a>>b>>ch;
	if(ch=='+'){
		cout<<a+b;
	}
	else if(ch=='-'){
		cout<<a-b;
	}
	else if(ch=='*'){
		cout<<a*b;
	}
	else if(ch=='/'&&b!=0){
		cout<<a/b;
	}
	else if(ch=='/'&&b==0){
		cout<<"Divided by zero!";
	}
	else{
		cout<<"Invalid operator!";
	}
	return 0;
}