main()
{
      float score;
      int num,a,b,c,d,e,i;
      a=b=c=d=e=0;
      i=0;
      printf("please input the total students.\n");
      scanf("%d",&num);
      printf("please input each student's score.\n");
      while(i<num)
      {
        scanf("%f",&score);
        if(score>100||score<0)
        (
        printf("error!repeat input\n");
        continue;
      }
      switch((int)(score/10))
      {
      case 10:
      case 9:a=a+1;break;
      case 8;b=b+1;break;
      case 7:c=c+1;break:
      case 6:d=d+1;break;
      case 5:
      case 4:
      case 3:
      case 2:
      case 1:
      case 0:e=e+1;break;
      }
      i=i+1;
      }
printf("over 90:%d\n",a);
printf("80~89:%d\n",b);
printf("70~79:%d\n",c);
printf("60~69:%d\n",d);
printf("below60:%d\n",e);
system("pause");
}

        printf("error!repeat input\n");
这一行报错
错误信息
39 D:\计算机\编程活动\3.4编程活动二 成绩管理.c [Warning] data definition has no type or storage class
找不到错误

39 D:\计算机\编程活动\3.4编程活动二 成绩管理.c syntax error before string constant
好像还有这个