#include<stdio.h>
 main()
 {
 int score[200];
 int counter1=0,counter2=0,counter3=0,counter4=0,counter5=0;
 int i=0;
 for(i=0;i<200;i++)
 {
 scanf("%d",&score[i]);
 if((score[i] == -1))
 break;
 else if(score[i]>=90)
 counter1++;
 else if(score[i]>=80)
 counter2++;
 else if(score[i]>=70)
 counter3++;
 else if(score[i]>=60)
 counter4++;
 else
 counter5++;
 }
 printf(" <60 is %d\n 60-69 is %d\n 70-79 is %d\n 80-89 is %d\n 90-100 is %d\n ",counter5,counter4,counter3,counter2,counter1);
 }

 
/*设班级每位同学有三门课程的考试成绩，
采用二维数组编程实现从键盘输入每个同学的成绩，并计算其平均成绩后输出*/
#include<stdio.h>
#define MAX 100 /*定义该学生成绩数组可接受的最大人数*/ 
main()
{	int i,j,n;
	float grade[MAX][4];
	printf("请输入学生人数：");
	scanf("%d",&n);
	for(i=0;i<n;i++)
	{	printf("请输入第%d个学生的三门课的分数:",i+1);
		for(j=0;j<3;j++)/*逐一输入第i个学生的成绩*/
			{ scanf("%f",&grade[i][j]); } 
			/*计算第i个学生的平均成绩*/
			grade[i][3]=(grade[i][0]+grade[i][1]+grade[i][2])/3; 
	} 
	printf("序号\t课程1\t课程2\t课程3\t平均成绩\n");
	for(i=0;i<n;i++)
	{	printf("%d\t%.1f\t%.1f\t%.1f\t%.1f\n",i+1,grade[i][0],grade[i][1],grade[i][2],grade[i][3]);	
	} 
}

#include “stdio.h”
 void main()
 { int score[200];
 intcounter1=0,counter2=0,counter3=0,counter4=0,counter5=0;
 int i=0; for(i=0;i<200;i++)
 { scanf("%d",&score[i]); if((score[i] == -1))
 break;
 else if(score[i]>=90)
 counter1++;
 else if(score[i]>=80) counter2++;
 else if(score[i]>=70) counter3++;
 else if(score[i]>=60) counter4++;
 else counter5++;
 }
 printf(" %d\n%d\n %d\n %d\n %d\n ",counter5,counter4,counter3,counter2,counter1);}

在这里插入代码片
#include "stdio.h"
main()
 { 
 	int a[100];
	 int counter1=0,counter2=0,counter3=0,counter4=0,counter5=0;
 	int i=0;
 	for(i=0;i<100;i++)
     {
             scanf("%d",&a[i]);
            if((a[i] == -1))
                 break;
            else if(score[i]>=90)
              counter1++;
            else if(score[i]>=80)
               counter2++;
            else if(score[i]>=70)
               counter3++;
            else if(score[i]>=60)
               counter4++;
            else 
               counter5++;
     }
 printf(" <60 is %d\n 60-69 is %d\n 70-79  is %d\n 80-89  is %d\n 90-100 is %d\n ",counter5,counter4,counter3,counter2,counter1);
}