#include<stdio.h>
void main()
{
int c,s;
float p,w,d,f;
scanf("%f,%f,%f",&p,&w,&s);
if(s>=3000)c=12;
else c=s/250;
switch(c)
{
    case 0:d=0;break;
    case 1:d=2;break;
    case 2:
    case 3:d=5;break;
    case 4:
    case 5:
        case 6:
            case 7:d=8;break;
            case 8:
                case 9:
                    case 10:
                        case 11:d=10;break;
                        case 12:d=15;break;
    }   
    f=p*w*s*(1-d/100.0);
    printf("freight=%15.4f\n",f);
}
书中给出输入100,20,300
输出应该是freight=    588000,0000
实际输出是freight=19276365824.0000

int c,s;
scanf("%f,%f,%f",&p,&w,&s);

int类型用的却是%f

知道了，谢谢你啊！