java依次输入10个学生成绩，判断学生（优秀、良好、中等、及格、不及格）并计算人数。

依次输入10个学生成绩，判断学生（优秀、良好、中等、及格、不及格）并计算人数。

判断成绩的标准分数是什么？

public static void main(String [] args){
        Scanner sc = new Scanner(System.in);
        int a,A=0,B=0,C=0,D=0,E=0;
        for (int i = 0; i < 10; i++) {
            System.out.print("输入第"+(i+1)+"个学生成绩：");
            a=sc.nextInt();
            if(a>=90&&a<=100){
                A++;
            }else if(a>=80&&a<90){
                B++;
            }else if(a>=70&&a<80){
                C++;
            }else if(a>=60&&a<70){
                D++;
            }else{
                E++;
            }
        }
        System.out.println("优秀："+A);
        System.out.println("良好："+B);
        System.out.println("中等："+C);
        System.out.println("及格："+D);
        System.out.println("不及格："+E);
    }

import java.util.*;
public class T1_3 {
    public static void main(String[] args){
        int i,count0=0,count1=0,count2=0,count3=0,count4=0,count5=0;
        //int grade=0;
        System.out.println("请输入10个0-100之间的数：");
        Scanner sc = new Scanner(System.in);
        int[] arr = new int[10];
        for(i=0;i<9;i++)
        {
            arr[i] = sc.nextInt();
        
        int grade = arr[i]/10;
        switch(grade)
        {
            case 10:count0++;break;
            case 9:count1++;break;
            case 8:count2++;break;
            case 7:count3++;break;
            case 6:count4++;break;
            default:count5++;break;
        }
        }    
        System.out.println(count0+count1+"个优秀。");
        System.out.println(count2+"个良好。");
        System.out.println(count3+"个中等。");
        System.out.println(count4+"个及格。");
        System.out.println(count5+"个不及格。");
    }
}

import java.util.*;

public class A {
    public static void main(String[] args) {
        int fre[] = new int[5];
        Scanner sc = new Scanner(System.in);
        for(int i = 0;i < 10;i++){
            int a = sc.nextInt();
            if(a >= 90){
                fre[0] ++;
            }else if(a >= 80){
                fre[1] ++;
            }else if(a >= 70){
                fre[2] ++;
            }else if(a >= 60){
                fre[3] ++;
            }else{
                fre[4] ++;
            }
        }
        sc.close();
        System.out.println("优秀、良好、中等、及格、不及格的人数分别为：" + fre[0] + " " + fre[1] + " " + fre[2] + " " + fre[3] + " " + fre[4]);
    }
}