C语言计算佣金

#include<stdio.h>
int main(void)
{
    int shares;
    float price,value,commission,rival_commission;


    printf("enter number of shares:");
    setvbuf(stdout,null,_ionbf,0);
    scanf("%d",&shares);
    printf("enter price per share:");
    scanf("%f",&price);


    value =shares*price;


    if(value<2500.00f)
        commission=30.00f+.007f*value;
    else if (value<6250.00f)
        commission=56.00f+.0066f*value;
    else if (value <20000.00f)
        commission=76.00f+.0024f*value;
    else if(value<50000.00f)
        commission=100.00f+.0022f*value;
    else if(value<50000.00f)
        commission=155.00f+.0011f*value;
    else
        commission=255.00f+.0009f*value;


    if(commission<39.00f)
        commission=39.00f;


    rival_commission=33.00f+(shares<2000?.03f:.02f);




    printf("the first broker's commission :$%.2f\n",commission);
    printf("the second broker's commission:$%.2f\n",rival_commission);


    if(commission<rival_commission)
    {
        printf("the first broker is the right one.\n");
    }
    else{
        printf("the second broker irus the right one.\n");
    }
    return 0;
}