60分求助

#include<stdio.h>
int main()
{
    int a;
    double sum=0;
    scanf("%d",&a);
    if(a<=150)
    {
        sum=a*0.4463;
    }
    else if(a>150&&a<=400)
    {
        sum=150*0.4463+(a-150)*0.4663;
    }
    else
    {
        sum=150*0.4463+(400-150)*0.4663+(a-150-400)*0.5663;
    }
    printf("%.1lf",sum);
    return 0;
}