题解 | #判断成绩等级#

#include <iostream>;break
#include<math.h>
using namespace std;

int main() {
    
    int score;
    cin >> score;
    if((score<0)||(score>100))
     cout<<"成绩不合法"<<endl;
    else{
        switch(score/10){
            case 9:case 10:
             cout<<"优秀" ;break;
            case 8:cout<<"良";break;
            case 7:cout<<"中";break;
            case 6:cout<<"及格";break;
            default:cout<<"差";
        }
    }
    return 0;

}

#include <iostream>
#include<math.h>
using namespace std;

int main() {
    
    int score;
    cin >> score;

    if((score>=90)&&(score<=100))
    cout<<"优秀";
    else if((score>=80 )&&(score<=89))
    cout<<"良";
    else if((score>=70 )&&(score<=79))
    cout<<"中";
    else if((score>=60 )&&(score<=69))
    cout<<"及格";
    else if((score>=0)&&(score<=59))
    cout<<"差";
    else if((score>100)||(score<0))
    cout<<"成绩不合法";
    return 0;

}