the variable'discount' is being used without being initialized

the variable'discount' is being used without being initialized
int _tmain(int argc,_TCHAR* argv[])
{float price,weigh,distance,f,discount;
int c;
printf("Please enter the price,weigh,distance:\n");
scanf("%lf%lf%lf",&price,&weigh,&distance);
if(distance>=3000)
c=12;
else c=distance/250;
switch(c)
{case 0:discount=0;break;
case 1:discount=2;break;
case 2:
case 3:discount=5;break;
case 4:
case 5:
case 6:
case 7:discount=8;break;
case 8:
case 9:
case 10:
case 11:discount=10;break;
case 12:discount=15;break;
default:printf("\!\n");}
f=price*distance*weigh*(1-discount/100);
printf("You have to pay %10.2f\n",f);
return 0;
}
dicount 已经被初始了啊
是discount