你们觉得呢？

#include<iostream> using namespace std; int main(){ int a; cin >> a; if (a >=90 and a<100) cout<<"A"; else if (a >=80 and a<90) cout<<"B"; else if (a >=70 and a<80) cout<<"C"; else if (a >=60 and a<70) cout<<"D"; else cout<<"E"; }