/*根據所輸入的成績判斷所處的等級*/
main()
{
	int score,grade;
        printf(“please inputn your score :  ”);
        scanf(“%d”,&score);
	if(score>=80)
            grade=1;
        else if(score>=60)
            grade=2;
        else  grade=3;
        switch(grade)
        {
		case 1: printf(“You are a perfect student !”);
            	case 2: printf(“Do not play so more !!”);
            	case 3: printf(“You must study harder !!!”);
   	}
}