C语言程序设计教程（第三版）课后习题5.6 （Java代码）

import java.util.Scanner;

public class Main {

        public static char Grade(int a){

                if(a>=90)

                        return 'A';

                else if(90>a&&a>=80)

                        return 'B';

                else if(80>a&&a>=70)

                        return 'C';

                else if(70>a&&a>=60)

                        return 'D';

                else

                        return 'E';

        }

        public static void main(String[] arg){

                Scanner sc = new Scanner(System.in);

                int a = sc.nextInt();

                System.out.print(Grade(a));

        }

}